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path: root/drivers/tty/serial/serial_core.c
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2025-06-19tty: serial: fix print format specifiersJoseph Tilahun
The serial info sometimes produces negative TX/RX counts. E.g.: 3: uart:FSL_LPUART mmio:0x02970000 irq:46 tx:-1595870545 rx:339619 RTS|CTS|DTR|DSR|CD It appears that the print format specifiers don't match with the types of the respective variables. E.g.: All of the fields in struct uart_icount are u32, but the format specifier used is %d, even though u32 is unsigned and %d is for signed integers. Update drivers/tty/serial/serial_core.c to use the proper format specifiers. Reference https://docs.kernel.org/core-api/printk-formats.html as the documentation for what format specifiers are the proper ones to use for a given C type. Signed-off-by: Joseph Tilahun <jtilahun@astranis.com> Link: https://lore.kernel.org/r/20250610065653.3750067-1-jtilahun@astranis.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-19serial: Remove unused uart_get_consoleDr. David Alan Gilbert
uart_get_console() has been unused since 2019's commit bd0d9d159988 ("serial: remove ks8695 driver") Remove it, and it's associated docs. Signed-off-by: "Dr. David Alan Gilbert" <linux@treblig.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250608154654.73994-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-17tty: introduce and use tty_port_tty_vhangup() helperJiri Slaby (SUSE)
This code (tty_get -> vhangup -> tty_put) is repeated on few places. Introduce a helper similar to tty_port_tty_hangup() (asynchronous) to handle even vhangup (synchronous). And use it on those places. In fact, reuse the tty_port_tty_hangup()'s code and call tty_vhangup() depending on a new bool parameter. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Oliver Neukum <oneukum@suse.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20250611100319.186924-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25serial: use uart_port_ref_lock() helperJiri Slaby (SUSE)
uart_get_icount() and uart_carrier_raised() open code uart_port_ref_lock(). Use the helper instead. The difference is we use _irqsave() variants of a spinlock now. But that's "safer" than _irq(). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250425111315.1036184-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25serial: rename local uart_port_lock() -> uart_port_ref_lock()Jiri Slaby (SUSE)
uart_port_lock() and uart_port_unlock() are (at the same time) defined as: * functions in include/linux/serial_core.h * macros in drivers/tty/serial/serial_core.c The former are sane uart port lock wrappers. The latter _lock() does something completely different: it inspects a uart_state, obtains a uart_port from it, and increases its reference count. And if that all succeeded, the port is locked too. Similarly, the _unlock() counterpart first unlocks and then decrements the refcount too. This state is REALLY CONFUSING. So rename the latter (local .c macros): * uart_port_lock() -> uart_port_ref_lock(), and * uart_port_unlock() -> uart_port_unlock_deref(). Now, the forbidden while-at-it part: convert from a macro to an inline -- do it here as the passed 'flags' have to be pointer to ulong now. So we avoid doubled changes on identical LOCs. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250425111315.1036184-5-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25serial: switch uart_port::iotype to enum uart_iotypeJiri Slaby (SUSE)
The inline-defined constants look weird. Instead, define a proper enum for them and type uart_port::iotype as that enum. This allows for proper checking in switch-case labels (somewhere, a default or UPIO_UNKNOWN label needs to be added/handled). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250425111315.1036184-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-02Merge tag 'tty-6.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the big set of serial and tty driver updates for 6.15-rc1. Include in here are the following: - more great tty layer cleanups from Jiri. Someday this will be done, but that's not going to be any year soon... - kdb debug driver reverts to fix a reported issue - lots of .dts binding updates for different devices with serial devices - lots of tiny updates and tweaks and a few bugfixes for different serial drivers. All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits) tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning serial: stm32: do not deassert RS485 RTS GPIO prematurely serial: 8250: add driver for NI UARTs dt-bindings: serial: snps-dw-apb-uart: document RZ/N1 binding without DMA serial: icom: fix code format problems serial: sh-sci: Save and restore more registers tty: serial: pl011: remove incorrect of_match_ptr annotation dt-bindings: serial: snps-dw-apb-uart: Add support for rk3562 tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register tty: caif: removed unused function debugfs_tx() serial: 8250_dma: terminate correct DMA in tx_dma_flush() tty: serial: fsl_lpuart: rename register variables more specifically tty: serial: fsl_lpuart: use port struct directly to simply code tty: serial: fsl_lpuart: Use u32 and u8 for register variables tty: serial: fsl_lpuart: disable transmitter before changing RS485 related registers tty: serial: 8250: Add Brainboxes XC devices dt-bindings: serial: fsl-lpuart: support i.MX94 tty: serial: 8250: Add some more device IDs dt-bindings: serial: samsung: add exynos7870-uart compatible serial: 8250_dw: Comment possible corner cases in serial_out() implementation ...
2025-03-27Merge tag 'printk-for-6.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - New option "printk.debug_non_panic_cpus" allows to store printk messages from non-panic CPUs during panic. It might be useful when panic() fails. It is disabled by default because it increases the chance to see the messages printed before panic() and on the panic-CPU. - New build option "CONFIG_NULL_TTY_DEFAULT_CONSOLE" allows to build kernel without the virtual terminal support which prefers ttynull over serial console. - Do not unblank suspended consoles. - Some code clean up. * tag 'printk-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk/panic: Add option to allow non-panic CPUs to write to the ring buffer. printk: Add an option to allow ttynull to be a default console device printk: Check CON_SUSPEND when unblanking a console printk: Rename console_start to console_resume printk: Rename console_stop to console_suspend printk: Rename resume_console to console_resume_all printk: Rename suspend_console to console_suspend_all
2025-03-20serial: switch change_irq and change_port to bool in uart_set_info()Jiri Slaby (SUSE)
change_irq and change_port are boolean variables. Mark them as such (instead of uint). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250317070046.24386-32-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20serial: pass struct uart_state to uart_line_info()Jiri Slaby (SUSE)
uart_line_info() wants to work with struct uart_state. Do not pass a driver and an index. Pass the precomputed struct directly. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250317070046.24386-27-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20serial: remove redundant tty_port_link_device()Jiri Slaby (SUSE)
The linking is done implicitly by tty_port_register_device_attr_serdev() few lines below. So drop this explicit tty_port_link_device(). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250317070046.24386-26-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-11printk: Rename console_start to console_resumeMarcos Paulo de Souza
The intent of console_start was to resume a previously suspended console, so rename it accordingly. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-4-0b878577f2e6@suse.com [pmladek@suse.com: Fixed typo in the commit message. Updated also new drm_log.c.] Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-03-11printk: Rename console_stop to console_suspendMarcos Paulo de Souza
The intent of console_stop was in fact to suspend it, so rename the function accordingly. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20250226-printk-renaming-v1-3-0b878577f2e6@suse.com [pmladek@suse.com: Fixed typo in the commit message. Updated also new drm_log.c] Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-01-28Merge tag 'driver-core-6.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and debugfs updates from Greg KH: "Here is the big set of driver core and debugfs updates for 6.14-rc1. Included in here is a bunch of driver core, PCI, OF, and platform rust bindings (all acked by the different subsystem maintainers), hence the merge conflict with the rust tree, and some driver core api updates to mark things as const, which will also require some fixups due to new stuff coming in through other trees in this merge window. There are also a bunch of debugfs updates from Al, and there is at least one user that does have a regression with these, but Al is working on tracking down the fix for it. In my use (and everyone else's linux-next use), it does not seem like a big issue at the moment. Here's a short list of the things in here: - driver core rust bindings for PCI, platform, OF, and some i/o functions. We are almost at the "write a real driver in rust" stage now, depending on what you want to do. - misc device rust bindings and a sample driver to show how to use them - debugfs cleanups in the fs as well as the users of the fs api for places where drivers got it wrong or were unnecessarily doing things in complex ways. - driver core const work, making more of the api take const * for different parameters to make the rust bindings easier overall. - other small fixes and updates All of these have been in linux-next with all of the aforementioned merge conflicts, and the one debugfs issue, which looks to be resolved "soon"" * tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits) rust: device: Use as_char_ptr() to avoid explicit cast rust: device: Replace CString with CStr in property_present() devcoredump: Constify 'struct bin_attribute' devcoredump: Define 'struct bin_attribute' through macro rust: device: Add property_present() saner replacement for debugfs_rename() orangefs-debugfs: don't mess with ->d_name octeontx2: don't mess with ->d_parent or ->d_parent->d_name arm_scmi: don't mess with ->d_parent->d_name slub: don't mess with ->d_name sof-client-ipc-flood-test: don't mess with ->d_name qat: don't mess with ->d_name xhci: don't mess with ->d_iname mtu3: don't mess wiht ->d_iname greybus/camera - stop messing with ->d_iname mediatek: stop messing with ->d_iname netdevsim: don't embed file_operations into your structs b43legacy: make use of debugfs_get_aux() b43: stop embedding struct file_operations into their objects carl9170: stop embedding file_operations into their objects ...
2025-01-03driver core: Constify API device_find_child() and adapt for various usagesZijun Hu
Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tty: serial: extract uart_change_port() from uart_set_info()Jiri Slaby (SUSE)
This "change_port" part of uart_set_info() is for no good reason inlined there. It makes the function rather hard to read. Therefore, extract it to a separate function. This allows for flattening the ifs (with short path "return"s) and avoiding two levels of indentation. Both making the code really flat and comprehesible. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20241211074933.92973-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tty: serial: get rid of exit label from uart_set_info()Jiri Slaby (SUSE)
The label is unneeded since 7ba2e769825f (tty: Split the serial_core helpers for setserial into two). Until then, there was a lock held in uart_set_info(). Now it is not, so we can remove the label. This involves reordering the code, so that it is clear what values are returned, where and why. Until now, it was really hard to follow. The "change_port" part of the function is extracted into a separate function in the next patch. This patch makes the transition there easier too. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20241211074933.92973-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tty: serial_core: use more guard(mutex)Jiri Slaby (SUSE)
Simplify 4 more functions using guard(mutex): uart_get_info(), console_store(), serial_core_add_one_port(), and serial_core_register_port(). Especially console_store() is now much less convoluted. In the others, we save some goto-s and even local variables are dropped in some. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20241211074933.92973-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-16serial: core: Switch to irq_get_nr_irqs()Bart Van Assche
Use the irq_get_nr_irqs() function instead of the global variable 'nr_irqs'. Prepare for changing 'nr_irqs' from an exported global variable into a variable with file scope. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241015190953.1266194-13-bvanassche@acm.org
2024-09-26Merge tag 'tty-6.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the "big" set of tty/serial driver updates for 6.12-rc1. Nothing major in here, just nice forward progress in the slow cleanup of the serial apis, and lots of other driver updates and fixes. Included in here are: - serial api updates from Jiri to make things more uniform and sane - 8250_platform driver cleanups - samsung serial driver fixes and updates - qcom-geni serial driver fixes from Johan for the bizarre UART engine that that chip seems to have. Hopefully it's in a better state now, but hardware designers still seem to come up with more ways to make broken UARTS 40+ years after this all should have finished. - sc16is7xx driver updates - omap 8250 driver updates - 8250_bcm2835aux driver updates - a few new serial driver bindings added - other serial minor driver updates All of these have been in linux-next for a long time with no reported problems" * tag 'tty-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (65 commits) tty: serial: samsung: Fix serial rx on Apple A7-A9 tty: serial: samsung: Fix A7-A11 serial earlycon SError tty: serial: samsung: Use bit manipulation macros for APPLE_S5L_* tty: rp2: Fix reset with non forgiving PCIe host bridges serial: 8250_aspeed_vuart: Enable module autoloading serial: qcom-geni: fix polled console corruption serial: qcom-geni: disable interrupts during console writes serial: qcom-geni: fix console corruption serial: qcom-geni: introduce qcom_geni_serial_poll_bitfield() serial: qcom-geni: fix arg types for qcom_geni_serial_poll_bit() soc: qcom: geni-se: add GP_LENGTH/IRQ_EN_SET/IRQ_EN_CLEAR registers serial: qcom-geni: fix false console tx restart serial: qcom-geni: fix fifo polling timeout tty: hvc: convert comma to semicolon mxser: convert comma to semicolon serial: 8250_bcm2835aux: Fix clock imbalance in PM resume serial: sc16is7xx: convert bitmask definitions to use BIT() macro serial: sc16is7xx: fix copy-paste errors in EFR_SWFLOWx_BIT constants serial: sc16is7xx: remove SC16IS7XX_MSR_DELTA_MASK serial: xilinx_uartps: Make cdns_rs485_supported static ...
2024-08-21serial: core: Introduce wrapper to set @uart_port->consJohn Ogness
Introduce uart_port_set_cons() as a wrapper to set @cons of a uart_port. The wrapper sets @cons under the port lock in order to prevent @cons from disappearing while another context is holding the port lock. This is necessary for a follow-up commit relating to the port lock wrappers, which rely on @cons not changing between lock and unlock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Tested-by: Théo Lebrun <theo.lebrun@bootlin.com> # EyeQ5, AMBA-PL011 Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240820063001.36405-12-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-14serial: use guards for simple mutex locksJiri Slaby (SUSE)
Guards can help to make the code more readable. So use it wherever they do so. On many places labels and 'ret' locals are eliminated completely. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20240808103549.429349-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-12Merge 6.11-rc3 into tty-nextGreg Kroah-Hartman
We need the tty/serial fixes in here to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-07serial: don't use uninitialized value in uart_poll_init()Jiri Slaby (SUSE)
Coverity reports (as CID 1536978) that uart_poll_init() passes uninitialized pm_state to uart_change_pm(). It is in case the first 'if' takes the true branch (does "goto out;"). Fix this and simplify the function by simple guard(mutex). The code needs no labels after this at all. And it is pretty clear that the code has not fiddled with pm_state at that point. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Fixes: 5e227ef2aa38 (serial: uart_poll_init() should power on the UART) Cc: stable@vger.kernel.org Cc: Douglas Anderson <dianders@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240805102046.307511-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-07serial: protect uart_port_dtr_rts() in uart_shutdown() tooJiri Slaby (SUSE)
Commit af224ca2df29 (serial: core: Prevent unsafe uart port access, part 3) added few uport == NULL checks. It added one to uart_shutdown(), so the commit assumes, uport can be NULL in there. But right after that protection, there is an unprotected "uart_port_dtr_rts(uport, false);" call. That is invoked only if HUPCL is set, so I assume that is the reason why we do not see lots of these reports. Or it cannot be NULL at this point at all for some reason :P. Until the above is investigated, stay on the safe side and move this dereference to the if too. I got this inconsistency from Coverity under CID 1585130. Thanks. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240805102046.307511-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31serial: core: check uartclk for zero to avoid divide by zeroGeorge Kennedy
Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uartclk gets set. Oops: divide error: 0000 PREEMPT SMP KASAN PTI RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580) Call Trace: <TASK> serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576 drivers/tty/serial/8250/8250_port.c:2589) serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502 drivers/tty/serial/8250/8250_port.c:2741) serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862) uart_change_line_settings (./include/linux/spinlock.h:376 ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222) uart_port_startup (drivers/tty/serial/serial_core.c:342) uart_startup (drivers/tty/serial/serial_core.c:368) uart_set_info (drivers/tty/serial/serial_core.c:1034) uart_set_info_user (drivers/tty/serial/serial_core.c:1059) tty_set_serial (drivers/tty/tty_io.c:2637) tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791) __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Reported-by: syzkaller <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: George Kennedy <george.kennedy@oracle.com> Rule: add Link: https://lore.kernel.org/stable/1721148848-9784-1-git-send-email-george.kennedy%40oracle.com Link: https://lore.kernel.org/r/1721219078-3209-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-04serial: core: Add serial_base_match_and_update_preferred_console()Tony Lindgren
Let's add serial_base_match_and_update_preferred_console() for consoles using DEVNAME:0.0 style naming. The earlier approach to add it caused issues in the kernel command line ordering as we were calling __add_preferred_console() again for the deferred consoles. Signed-off-by: Tony Lindgren <tony.lindgren@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240703100615.118762-3-tony.lindgren@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25Revert "serial: core: Add support for DEVNAME:0.0 style naming for kernel ↵Greg Kroah-Hartman
console" This reverts commit 787a1cabac01c99846070fcf702e53befaf89f79. Let's roll back all of the serial core and printk console changes that went into 6.10-rc1 as there still are problems with them that need to be sorted out. Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1 Reported-by: Petr Mladek <pmladek@suse.com> Reported-by: Tony Lindgren <tony@atomide.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-04serial: drop debugging WARN_ON_ONCE() from uart_write()Tetsuo Handa
syzbot is reporting lockdep warning upon int disc = 7; ioctl(open("/dev/ttyS3", O_RDONLY), TIOCSETD, &disc); sequence. Do like what commit 5f1149d2f4bf ("serial: drop debugging WARN_ON_ONCE() from uart_put_char()") does. Reported-by: syzbot+f78380e4eae53c64125c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f78380e4eae53c64125c Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/d775ae2d-a2ac-439e-8e2b-134749f60f30@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-10serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()Hans de Goede
If a serdev_device_driver is already loaded for a serdev_tty_port when it gets registered by tty_port_register_device_attr_serdev() then that driver's probe() method will be called immediately. The serdev_device_driver's probe() method should then be able to call serdev_device_open() successfully, but because UPF_DEAD is still dead serdev_device_open() will fail with -ENXIO in this scenario: serdev_device_open() ctrl->ops->open() /* this callback being ttyport_open() */ tty->ops->open() /* this callback being uart_open() */ tty_port_open() port->ops->activate() /* this callback being uart_port_activate() */ Find bit UPF_DEAD is set in uport->flags and fail with errno -ENXIO. Fix this be clearing UPF_DEAD before tty_port_register_device_attr_serdev() note this only moves up the UPD_DEAD clearing a small bit, before: tty_port_register_device_attr_serdev(); mutex_unlock(&tty_port.mutex); uart_port.flags &= ~UPF_DEAD; mutex_unlock(&port_mutex); after: uart_port.flags &= ~UPF_DEAD; tty_port_register_device_attr_serdev(); mutex_unlock(&tty_port.mutex); mutex_unlock(&port_mutex); Reported-by: Weifeng Liu <weifeng.liu.z@gmail.com> Closes: https://lore.kernel.org/platform-driver-x86/20240505130800.2546640-1-weifeng.liu.z@gmail.com/ Tested-by: Weifeng Liu <weifeng.liu.z@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20240509141549.63704-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-04serial: core: Call device_set_awake_path() for console portClaudiu Beznea
In case the UART port is used as a console, no_console_suspend is available in bootargs and UART port is part of a software-controlled power domain we need to call device_set_awake_path(). This lets the power domain core code know that this domain should not be powered off during system suspend. Otherwise, the UART port power domain is turned off, nothing is printed while suspending and the suspend/resume process is blocked. This was detected on the Renesas RZ/G3S SoC while adding support for power domains. Based on code investigation (on v6.9-rc5), this issue is present on other SoCs (e.g., Renesas R-Mobile A1 [1], IMX8QXP [2]) and different SoCs have particular implementation to handle it. Due to this the patch added the call of device_set_awake_path() in uart_suspend_port() instead of having it in the platform specific UART driver. [1] drivers/pmdomain/renesas/rmobile-sysc.c:116 [2] drivers/pmdomain/imx/scu-pd.c:357 Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Tony Lindgren <tony.lindgren@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20240430095930.2806067-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-23Merge 6.9-rc5 into tty-nextGreg Kroah-Hartman
We want the tty fixes in here as well, and it resolves a merge conflict in: drivers/tty/serial/serial_core.c as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-17serial: core: Extract uart_alloc_xmit_buf() and uart_free_xmit_buf()Andy Shevchenko
After conversion to the kfifo, it becomes possible to extract two helper functions for better maintenance and code deduplication. Do it here. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240409174057.1104262-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-17serial: drop debugging WARN_ON_ONCE() from uart_put_char()Jiri Slaby (SUSE)
Pengfei Xu reports, that the -next commit 1788cf6a91d9 (tty: serial: switch from circ_buf to kfifo) tries to emit a WARNING and that leads to lockdep errors. Obviously we cannot print anything from uart_put_char()! This WARN_ON_ONCE() was/is a debug aid to check if the condition in uart_put_char() can happen at all. Pengfei Xu confirmed it can. Unlike me and kbuild bot in my queue. Second, I completely forgot about it, so I did not remove it in the final version, nor mentioned it in the commit log. Drop it now as we are all good. And we even have stack traces (and a reproducer)! Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Reported-by: Pengfei Xu <pengfei.xu@intel.com> Link: https://lore.kernel.org/r/20240416071904.21440-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-11serial: core: Fix missing shutdown and startup for serial base portTony Lindgren
We are seeing start_tx being called after port shutdown as noted by Jiri. This happens because we are missing the startup and shutdown related functions for the serial base port. Let's fix the issue by adding startup and shutdown functions for the serial base port to block tx flushing for the serial base port when the port is not in use. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Cc: stable <stable@kernel.org> Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240411055848.38190-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09serial: core: Clearing the circular buffer before NULLifying itAndy Shevchenko
The circular buffer is NULLified in uart_tty_port_shutdown() under the spin lock. However, the PM or other timer based callbacks may still trigger after this event without knowning that buffer pointer is not valid. Since the serial code is a bit inconsistent in checking the buffer state (some rely on the head-tail positions, some on the buffer pointer), it's better to have both aligned, i.e. buffer pointer to be NULL and head-tail possitions to be the same, meaning it's empty. This will prevent asynchronous calls to dereference NULL pointer as reported recently in 8250 case: BUG: kernel NULL pointer dereference, address: 00000cf5 Workqueue: pm pm_runtime_work EIP: serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) ... ? serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) __start_tx (drivers/tty/serial/8250/8250_port.c:1551) serial8250_start_tx (drivers/tty/serial/8250/8250_port.c:1654) serial_port_runtime_suspend (include/linux/serial_core.h:667 drivers/tty/serial/serial_port.c:63) __rpm_callback (drivers/base/power/runtime.c:393) ? serial_port_remove (drivers/tty/serial/serial_port.c:50) rpm_suspend (drivers/base/power/runtime.c:447) The proposed change will prevent ->start_tx() to be called during suspend on shut down port. Fixes: 43066e32227e ("serial: port: Don't suspend if the port is still busy") Cc: stable <stable@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202404031607.2e92eebe-lkp@intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240404150034.41648-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09serial: core: Fix regression when runtime PM is not enabledTony Lindgren
Commit 45a3a8ef8129 ("serial: core: Revert checks for tx runtime PM state") caused a regression for Sun Ultra 60 for the sunsab driver as reported by Nick Bowler <nbowler@draconx.ca>. We need to add back the check runtime PM enabled state for serial port controller device, I wrongly assumed earlier we could just remove it. Fixes: 45a3a8ef8129 ("serial: core: Revert checks for tx runtime PM state") Cc: stable <stable@kernel.org> Reported-by: Nick Bowler <nbowler@draconx.ca> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240325071649.27040-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09serial: core: Add support for DEVNAME:0.0 style naming for kernel consoleTony Lindgren
We can now add hardware based addressing for serial ports. Starting with commit 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM"), and all the related fixes to this commit, the serial core now knows to which serial port controller the ports are connected. The serial ports can be addressed with DEVNAME:0.0 style naming. The names are something like 00:04:0.0 for a serial port on qemu, and something like 2800000.serial:0.0 on platform device using systems like ARM64 for example. The DEVNAME is the unique serial port hardware controller device name, AKA the name for port->dev. The 0.0 are the serial core controller id and port id. Typically 0.0 are used for each controller and port instance unless the serial port hardware controller has multiple controllers or ports. Using DEVNAME:0.0 style naming actually solves two long term issues for addressing the serial ports: 1. According to Andy Shevchenko, using DEVNAME:0.0 style naming fixes an issue where depending on the BIOS settings, the kernel serial port ttyS instance number may change if HSUART is enabled 2. Device tree using architectures no longer necessarily need to specify aliases to find a specific serial port, and we can just allocate the ttyS instance numbers dynamically in whatever probe order To do this, let's match the hardware addressing style console name to the character device name used, and add a preferred console using the character device name. Note that when using console=DEVNAME:0.0 style kernel command line, the 8250 serial console gets enabled later compared to using console=ttyS naming for ISA ports. This is because the serial port DEVNAME to character device mapping is not known until the serial driver probe time. If used together with earlycon, this issue is avoided. Signed-off-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Dhruva Gole <d-gole@ti.com> Link: https://lore.kernel.org/r/20240327110021.59793-5-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09tty: serial: switch from circ_buf to kfifoJiri Slaby (SUSE)
Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example. Kfifo API can also fill in scatter-gather DMA structures, so it easier for that use case too. Look at lpuart_dma_tx() for example. Note that not all drivers can be converted to that (like atmel_serial), they handle DMA specially. Note that usb-serial uses kfifo for TX for ages. omap needed a bit more care as it needs to put a char into FIFO to start the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to do kfifo_dma_out_prepare twice: once to find out the tx_size (to find out if it is worths to do DMA at all -- size >= 4), the second time for the actual transfer. All traces of circ_buf are removed from serial_core.h (and its struct uart_state). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Al Cooper <alcooperx@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Cc: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Pali Rohár <pali@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hammer Hsieh <hammerh0314@gmail.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@kernel.org> Cc: Michal Simek <michal.simek@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-05serial: Lock console when calling into driver before registrationPeter Collingbourne
During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27serial: core: Fix atomicity violation in uart_tiocmgetGui-Dong Han
In uart_tiocmget(): result = uport->mctrl; uart_port_lock_irq(uport); result |= uport->ops->get_mctrl(uport); uart_port_unlock_irq(uport); ... return result; In uart_update_mctrl(): uart_port_lock_irqsave(port, &flags); ... port->mctrl = (old & ~clear) | set; ... port->ops->set_mctrl(port, port->mctrl); ... uart_port_unlock_irqrestore(port, flags); An atomicity violation is identified due to the concurrent execution of uart_tiocmget() and uart_update_mctrl(). After assigning result = uport->mctrl, the mctrl value may change in uart_update_mctrl(), leading to a mismatch between the value returned by uport->ops->get_mctrl(uport) and the mctrl value previously read. This can result in uart_tiocmget() returning an incorrect value. This possible bug is found by an experimental static analysis tool developed by our team, BassCheck[1]. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. The above possible bug is reported when our tool analyzes the source code of Linux 5.17. To address this issue, it is suggested to move the line result = uport->mctrl inside the uart_port_lock block to ensure atomicity and prevent the mctrl value from being altered during the execution of uart_tiocmget(). With this patch applied, our tool no longer reports the bug, with the kernel configuration allyesconfig for x86_64. Due to the absence of the requisite hardware, we are unable to conduct runtime testing of the patch. Therefore, our verification is solely based on code logic analysis. [1] https://sites.google.com/view/basscheck/ Fixes: c5f4644e6c8b ("[PATCH] Serial: Adjust serial locking") Cc: stable@vger.kernel.org Signed-off-by: Gui-Dong Han <2045gemini@gmail.com> Link: https://lore.kernel.org/r/20240112113624.17048-1-2045gemini@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core, imx: do not set RS485 enabled if it is not supportedLino Sanfilippo
If the imx driver cannot support RS485 it nullifies the ports rs485_supported structure. But it still calls uart_get_rs485_mode() which may set the RS485_ENABLED flag nevertheless. This may lead to an attempt to configure RS485 even if it is not supported when the flag is evaluated in uart_configure_port() at port startup. Avoid this by bailing out of uart_get_rs485_mode() if the RS485_ENABLED flag is not supported by the caller. With this fix a check for RTS availability is now obsolete in the imx driver, since it can not evaluate to true any more. So remove this check. Furthermore the explicit nullifcation of rs485_supported is not needed, since the memory has already been set to zeros at allocation. So remove this, too. Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240103061818.564-6-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: make sure RS485 cannot be enabled when it is not supportedLino Sanfilippo
Some uart drivers specify a rs485_config() function and then decide later to disable RS485 support for some reason (e.g. imx and ar933). In these cases userspace may be able to activate RS485 via TIOCSRS485 nevertheless, since in uart_set_rs485_config() an existing rs485_config() function indicates that RS485 is supported. Make sure that this is not longer possible by checking the uarts rs485_supported.flags instead and bailing out if SER_RS485_ENABLED is not set. Furthermore instead of returning an empty structure return -ENOTTY if the RS485 configuration is requested via TIOCGRS485 but RS485 is not supported. This has a small impact on userspace visibility but it is consistent with the -ENOTTY error for TIOCGRS485. Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported") Fixes: 55e18c6b6d42 ("serial: imx: Remove serial_rs485 sanitization") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-5-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: fix sanitizing check for RTS settingsLino Sanfilippo
Among other things uart_sanitize_serial_rs485() tests the sanity of the RTS settings in a RS485 configuration that has been passed by userspace. If RTS-on-send and RTS-after-send are both set or unset the configuration is adjusted and RTS-after-send is disabled and RTS-on-send enabled. This however makes only sense if both RTS modes are actually supported by the driver. With commit be2e2cb1d281 ("serial: Sanitize rs485_struct") the code does take the driver support into account but only checks if one of both RTS modes are supported. This may lead to the errorneous result of RTS-on-send being set even if only RTS-after-send is supported. Fix this by changing the implemented logic: First clear all unsupported flags in the RS485 configuration, then adjust an invalid RTS setting by taking into account which RTS mode is supported. Cc: <stable@vger.kernel.org> Fixes: be2e2cb1d281 ("serial: Sanitize rs485_struct") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-4-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: set missing supported flag for RX during TX GPIOLino Sanfilippo
If the RS485 feature RX-during-TX is supported by means of a GPIO set the according supported flag. Otherwise setting this feature from userspace may not be possible, since in uart_sanitize_serial_rs485() the passed RS485 configuration is matched against the supported features and unsupported settings are thereby removed and thus take no effect. Cc: <stable@vger.kernel.org> Fixes: 163f080eb717 ("serial: core: Add option to output RS485 RX_DURING_TX state via GPIO") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-3-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: Do not hold the port lock when setting rx-during-tx GPIOLino Sanfilippo
Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config(). Since this function is called with the port lock held, this can be a problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Also with commit c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04tty: serial: kgdboc: Fix 8250_* kgdb over serialMichael Trimarchi
Check if port type is not PORT_UNKNOWN during poll_init. The kgdboc calls the tty_find_polling_driver that check if the serial is able to use poll_init. The poll_init calls the uart uart_poll_init that try to configure the uart with the selected boot parameters. The uart must be ready before setting parameters. Seems that PORT_UNKNOWN is already used by other functions in serial_core to detect uart status, so use the same to avoid to use it in invalid state. The crash happen for instance in am62x architecture where the 8250 register the platform driver after the 8250 core is initialized. Follow the report crash coming from KGDB Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt This section of the code is too early because in this case the omap serial is not probed Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt 0 _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 1 logic_outb (value=0 '\000', addr=18446739675637874689) at lib/logic_pio.c:299 2 0xffff80008082dfcc in io_serial_out (p=0x0, offset=16760830, value=0) at drivers/tty/serial/8250/8250_port.c:416 3 0xffff80008082fe34 in serial_port_out (value=<optimized out>, offset=<optimized out>, up=<optimized out>) at ./include/linux/serial_core.h:677 4 serial8250_do_set_termios (port=0xffff8000828ee940 <serial8250_ports+1568>, termios=0xffff80008292b93c, old=0x0) at drivers/tty/serial/8250/8250_port.c:2860 5 0xffff800080830064 in serial8250_set_termios (port=0xfffffbfffe800000, termios=0xffbffe, old=0x0) at drivers/tty/serial/8250/8250_port.c:2912 6 0xffff80008082571c in uart_set_options (port=0xffff8000828ee940 <serial8250_ports+1568>, co=0x0, baud=115200, parity=110, bits=8, flow=110) at drivers/tty/serial/serial_core.c:2285 7 0xffff800080828434 in uart_poll_init (driver=0xfffffbfffe800000, line=16760830, options=0xffff8000828f7506 <config+6> "115200n8") at drivers/tty/serial/serial_core.c:2656 8 0xffff800080801690 in tty_find_polling_driver (name=0xffff8000828f7500 <config> "ttyS2,115200n8", line=0xffff80008292ba90) at drivers/tty/tty_io.c:410 9 0xffff80008086c0b0 in configure_kgdboc () at drivers/tty/serial/kgdboc.c:194 10 0xffff80008086c1ec in kgdboc_probe (pdev=0xfffffbfffe800000) at drivers/tty/serial/kgdboc.c:249 11 0xffff8000808b399c in platform_probe (_dev=0xffff000000ebb810) at drivers/base/platform.c:1404 12 0xffff8000808b0b44 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:579 13 really_probe (dev=0xffff000000ebb810, drv=0xffff80008277f138 <kgdboc_platform_driver+48>) at drivers/base/dd.c:658 14 0xffff8000808b0d2c in __driver_probe_device (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, dev=0xffff000000ebb810) at drivers/base/dd.c:800 15 0xffff8000808b0eb8 in driver_probe_device (drv=0xfffffbfffe800000, dev=0xffff000000ebb810) at drivers/base/dd.c:830 16 0xffff8000808b0ff4 in __device_attach_driver (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, _data=0xffff80008292bc48) at drivers/base/dd.c:958 17 0xffff8000808ae970 in bus_for_each_drv (bus=0xfffffbfffe800000, start=0x0, data=0xffff80008292bc48, fn=0xffff8000808b0f3c <__device_attach_driver>) at drivers/base/bus.c:457 18 0xffff8000808b1408 in __device_attach (dev=0xffff000000ebb810, allow_async=true) at drivers/base/dd.c:1030 19 0xffff8000808b16d8 in device_initial_probe (dev=0xfffffbfffe800000) at drivers/base/dd.c:1079 20 0xffff8000808af9f4 in bus_probe_device (dev=0xffff000000ebb810) at drivers/base/bus.c:532 21 0xffff8000808ac77c in device_add (dev=0xfffffbfffe800000) at drivers/base/core.c:3625 22 0xffff8000808b3428 in platform_device_add (pdev=0xffff000000ebb800) at drivers/base/platform.c:716 23 0xffff800081b5dc0c in init_kgdboc () at drivers/tty/serial/kgdboc.c:292 24 0xffff800080014db0 in do_one_initcall (fn=0xffff800081b5dba4 <init_kgdboc>) at init/main.c:1236 25 0xffff800081b0114c in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1298 26 do_initcalls () at init/main.c:1314 27 do_basic_setup () at init/main.c:1333 28 kernel_init_freeable () at init/main.c:1551 29 0xffff8000810271ec in kernel_init (unused=0xfffffbfffe800000) at init/main.c:1441 30 0xffff800080015e80 in ret_from_fork () at arch/arm64/kernel/entry.S:857 Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Link: https://lore.kernel.org/r/20231224131200.266224-1-michael@amarulasolutions.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04tty: serial: Add RS422 flag to struct serial_rs485Crescent CY Hsieh
Add "SER_RS485_MODE_RS422" flag to struct serial_rs485, so that serial port can switch interface into RS422 if supported by using ioctl command "TIOCSRS485". By treating RS422 as a mode of RS485, which means while enabling RS422 there are two flags need to be set (SER_RS485_ENABLED and SER_RS485_MODE_RS422), it would make things much easier. For example some places that checks for "SER_RS485_ENABLED" won't need to be rewritten. Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> Link: https://lore.kernel.org/r/20231201071554.258607-3-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: Clean up uart_update_timeout() functionVamshi Gajjela
Rename the variable size to temp and change its data type from unsigned int to u64 to avoid type casting in multiplication. Remove the intermediate variable frame_time and use temp instead to accommodate the nanoseconds(ns). port->frame_time is an unsigned int, therefore an explicit cast is used to improve readability. Having said this unsigned int is sufficinet to hold frame time duration in nanoseconds for all the standard baudrates. Consider 9600 baud, it takes 1/9600 seconds for one bit, for a total of 10 bits (start, 8-bit data, stop) 10/9600=1.04 ms for 1 byte transfer, frame_time here is 1041667ns. As baudrate increases frame_time decreases, say for 115200 baud it is 86806ns. To avoid costly 64-bit arithmetic we do not upconvert the type for variable frame_time as overflow happens for extremely low baudrates which are impractical and are not used in real-world applications. Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231109063417.3971005-3-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-08tty: make tty_operations::send_xchar accept u8 charJiri Slaby (SUSE)
tty_operations::send_xchar is one of the last users of 'char' type for characters in the tty layer. Convert it to u8 now. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: netdev@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-bluetooth@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20231206073712.17776-5-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-03 14:29:17 +0000