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path: root/drivers/tty/serial/8250
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2023-03-09serial: 8250_pci1xxxx: Disable SERIAL_8250_PCI1XXXX config by defaultKumaravel Thiagarajan
Commit 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart support") made the SERIAL_8250_PCI1XXXX driver enabled when SERIAL_8250 is enabled, disable it as this driver does not need to be enabled by default Fixes: 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart support") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/lkml/CAHk-=whhFCeeuo6vTEmNSx6S-KKkugxgzN_W5Z6v-9yH9gc3Zw@mail.gmail.com/ Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20230305145124.13444-1-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09serial: 8250_fsl: fix handle_irq lockingJohan Hovold
The 8250 handle_irq callback is not just called from the interrupt handler but also from a timer callback when polling (e.g. for ports without an interrupt line). Consequently the callback must explicitly disable interrupts to avoid a potential deadlock with another interrupt in polled mode. Fix up the two paths in the freescale callback that failed to re-enable interrupts when polling. Fixes: 853a9ae29e97 ("serial: 8250: fix handle_irq locking") Cc: stable@vger.kernel.org # 5.13 Reported-by: Dan Carpenter <error27@gmail.com> Link: https://lore.kernel.org/r/Y/xYzqp4ogmOF5t0@kili Signed-off-by: Johan Hovold <johan@kernel.org> Acked-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230227085046.24282-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09serial: 8250_em: Fix UART port typeBiju Das
As per HW manual for EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART IP found on EMMA mobile SoC is Register-compatible with the general-purpose 16750 UART chip. Fix UART port type as 16750 and enable 64-bytes fifo support. Fixes: 22886ee96895 ("serial8250-em: Emma Mobile UART driver V2") Cc: stable@vger.kernel.org Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09serial: 8250: ASPEED_VUART: select REGMAP instead of depending on itRandy Dunlap
REGMAP is a hidden (not user visible) symbol. Users cannot set it directly thru "make *config", so drivers should select it instead of depending on it if they need it. Consistently using "select" or "depends on" can also help reduce Kconfig circular dependency issues. Therefore, change the use of "depends on REGMAP" to "select REGMAP". Fixes: 8d310c9107a2 ("drivers/tty/serial/8250: Make Aspeed VUART SIRQ polarity configurable") Cc: stable <stable@kernel.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Oskar Senft <osk@google.com> Cc: linux-serial@vger.kernel.org Link: https://lore.kernel.org/r/20230226053953.4681-9-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08serial: 8250_pci1xxxx: Add power management functions to quad-uart driverKumaravel Thiagarajan
pci1xxxx's quad-uart function has the capability to wake up UART from suspend state. Enable wakeup before entering into suspend and disable wakeup on resume. Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Link: https://lore.kernel.org/r/20230207164814.3104605-5-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08serial: 8250_pci1xxxx: Add RS485 support to quad-uart driverKumaravel Thiagarajan
pci1xxxx uart supports RS485 mode of operation in the hardware with auto-direction control with configurable delay for releasing RTS after the transmission. This patch adds support for the RS485 mode. Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230207164814.3104605-4-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08serial: 8250_pci1xxxx: Add driver for quad-uart supportKumaravel Thiagarajan
pci1xxxx is a PCIe switch with a multi-function endpoint on one of its downstream ports. Quad-uart is one of the functions in the multi-function endpoint. This driver loads for the quad-uart and enumerates single or multiple instances of uart based on the PCIe subsystem device ID. Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230207164814.3104605-3-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08serial: 8250_pci: Add serial8250_pci_setup_port definition in 8250_pcilib.cKumaravel Thiagarajan
Move implementation of setup_port func() to serial8250_pci_setup_port. Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230207164814.3104605-2-kumaravel.thiagarajan@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06Merge 6.2-rc7 into tty-nextGreg Kroah-Hartman
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-02serial: 8250: Fix mismerge regarding serial_lsr_in()Uwe Kleine-König
The relevant history introducing serial_lsr_in() looks as follows: $ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c * df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next |\ | * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read * | ... * | bdb70c424df1 serial: 8250: Create serial_lsr_in() * | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read * | ... |/ o 9fafe733514b tty: remove CMSPAR ifdefs So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was introduced twice and in one branch it was followed up by commit bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved explicit lsr_saved_flags handling into a new function serial_lsr_in(). When the two branches were merged in commit df36f3e3fbb7, we got both, serial_lsr_in() and the explicit lsr_saved_flags handling. So drop the explicit lsr_saved_flags handling. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230202104501.264686-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-31serial: 8250_dma: Fix DMA Rx rearm raceIlpo Järvinen
As DMA Rx can be completed from two places, it is possible that DMA Rx completes before DMA completion callback had a chance to complete it. Once the previous DMA Rx has been completed, a new one can be started on the next UART interrupt. The following race is possible (uart_unlock_and_check_sysrq_irqrestore() replaced with spin_unlock_irqrestore() for simplicity/clarity): CPU0 CPU1 dma_rx_complete() serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma_flush() __dma_rx_complete() dma->rx_running = 0 // Complete DMA Rx spin_unlock_irqrestore(&port->lock) serial8250_handle_irq() spin_lock_irqsave(&port->lock) handle_rx_dma() serial8250_rx_dma() dma->rx_running = 1 // Setup a new DMA Rx spin_unlock_irqrestore(&port->lock) spin_lock_irqsave(&port->lock) // sees dma->rx_running = 1 __dma_rx_complete() dma->rx_running = 0 // Incorrectly complete // running DMA Rx This race seems somewhat theoretical to occur for real but handle it correctly regardless. Check what is the DMA status before complething anything in __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-31serial: 8250_dma: Fix DMA Rx completion raceIlpo Järvinen
__dma_rx_complete() is called from two places: - Through the DMA completion callback dma_rx_complete() - From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT The former does not hold port's lock during __dma_rx_complete() which allows these two to race and potentially insert the same data twice. Extend port's lock coverage in dma_rx_complete() to prevent the race and check if the DMA Rx is still pending completion before calling into __dma_rx_complete(). Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Tested-by: Gilles BULOZ <gilles.buloz@kontron.com> Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-22Merge 6.2-rc5 into tty-nextGreg Kroah-Hartman
We need the serial/tty changes into this branch as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-20serial: exar: Add support for Sealevel 7xxxC serial cardsMatthew Howell
Add support for Sealevel 7xxxC serial cards. This patch: * Adds IDs to recognize 7xxxC cards from Sealevel Systems. * Updates exar_pci_probe() to set nr_ports to last two bytes of primary dev ID for these cards. Signed-off-by: Matthew Howell <matthew.howell@sealevel.com> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2301191440010.22558@tstest-VirtualBox Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19tty: serial: 8250: add DFL bus driver for Altera 16550.Matthew Gerlach
Add a Device Feature List (DFL) bus driver for the Altera 16550 implementation of UART. Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Marco Pagani <marpagan@redhat.com> Link: https://lore.kernel.org/r/20230115151447.1353428-5-matthew.gerlach@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: 8250_early: Convert literals to use definesIlpo Järvinen
Use existing defines for the serial register values in 8250_early. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221125130509.8482-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: 8250: Define IIR 64 byte bit & cleanup related codeIlpo Järvinen
16750 indicates 64 bytes FIFO with a IIR bit. Add define for it and make related code more obvious. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221125130509.8482-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: 8250: Add IIR FIFOs enabled field properlyIlpo Järvinen
Don't use magic literals & comments but define a real field instead for UART_IIR_FIFO_ENABLED and name also the values. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221125130509.8482-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: 8250: Cleanup MCR literalsIlpo Järvinen
Use proper names from MCR bits. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221125130509.8482-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: 8250: Name MSR literalsIlpo Järvinen
Add UART_MSR_STATUS_BITS for CD, RI, DSR & CTS. Use names for the literal. Don't make the define for combined flags part of UAPI. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221125130509.8482-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19serial: 8250: Use defined IER bitsIlpo Järvinen
Instead of literal 0x0f, add a define for enabling all IER bits the 8250 driver is interested in. Don't make the define for combined flags part of UAPI. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221125130509.8482-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-16Merge tag 'tty-6.2-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 changes for 6.2-rc1. As in previous kernel releases, nothing big here at all, just some small incremental serial/tty layer cleanups and some individual driver additions and fixes. Highlights are: - serial helper macros from Jiri Slaby to reduce the amount of duplicated code in serial drivers - api cleanups and consolidations from Ilpo Järvinen in lots of serial drivers - the usual set of n_gsm fixes from Daniel Starke as that code gets exercised more - TIOCSTI is finally able to be disabled if requested (security hardening feature from Kees Cook) - fsl_lpuart driver fixes and features added - other small serial driver additions and fixes All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits) serial: atmel: don't stop the transmitter when doing PIO serial: atmel: cleanup atmel_start+stop_tx() tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API serial: sunsab: Fix error handling in sunsab_init() serial: altera_uart: fix locking in polling mode serial: pch: Fix PCI device refcount leak in pch_request_dma() tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused tty: serial: fsl_lpuart: Add runtime pm support tty: serial: fsl_lpuart: enable wakeup source for lpuart serdev: Replace poll loop by readx_poll_timeout() macro tty: synclink_gt: unwind actions in error path of net device open serial: stm32: move dma_request_chan() before clk_prepare_enable() dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity' serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle. serial: amba-pl011: avoid SBSA UART accessing DMACR register tty: serial: altera_jtaguart: remove struct altera_jtaguart tty: serial: altera_jtaguart: use uart_port::read_status_mask tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars() n_tty: Rename tail to old_tail in n_tty_read() ...
2022-12-12Merge tag 'printk-for-6.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Add NMI-safe SRCU reader API. It uses atomic_inc() instead of this_cpu_inc() on strong load-store architectures. - Introduce new console_list_lock to synchronize a manipulation of the list of registered consoles and their flags. This is a first step in removing the big-kernel-lock-like behavior of console_lock(). This semaphore still serializes console->write() calbacks against: - each other. It primary prevents potential races between early and proper console drivers using the same device. - suspend()/resume() callbacks and init() operations in some drivers. - various other operations in the tty/vt and framebufer susbsystems. It is likely that console_lock() serializes even operations that are not directly conflicting with the console->write() callbacks here. This is the most complicated big-kernel-lock aspect of the console_lock() that will be hard to untangle. - Introduce new console_srcu lock that is used to safely iterate and access the registered console drivers under SRCU read lock. This is a prerequisite for introducing atomic console drivers and console kthreads. It will reduce the complexity of serialization against normal consoles and console_lock(). Also it should remove the risk of deadlock during critical situations, like Oops or panic, when only atomic consoles are registered. - Check whether the console is registered instead of enabled on many locations. It was a historical leftover. - Cleanly force a preferred console in xenfb code instead of a dirty hack. - A lot of code and comment clean ups and improvements. * tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits) printk: htmldocs: add missing description tty: serial: sh-sci: use setup() callback for early console printk: relieve console_lock of list synchronization duties tty: serial: kgdboc: use console_list_lock to trap exit tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console() tty: serial: kgdboc: use console_list_lock for list traversal tty: serial: kgdboc: use srcu console list iterator proc: consoles: use console_list_lock for list iteration tty: tty_io: use console_list_lock for list synchronization printk, xen: fbfront: create/use safe function for forcing preferred netconsole: avoid CON_ENABLED misuse to track registration usb: early: xhci-dbc: use console_is_registered() tty: serial: xilinx_uartps: use console_is_registered() tty: serial: samsung_tty: use console_is_registered() tty: serial: pic32_uart: use console_is_registered() tty: serial: earlycon: use console_is_registered() tty: hvc: use console_is_registered() efi: earlycon: use console_is_registered() tty: nfcon: use console_is_registered() serial_core: replace uart_console_enabled() with uart_console_registered() ...
2022-12-02serial_core: replace uart_console_enabled() with uart_console_registered()John Ogness
All users of uart_console_enabled() really want to know if a console is registered. It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. A _locked() variant is provided because uart_set_options() is always called with the console_list_lock held and must check if a console is registered in order to synchronize with kgdboc. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
2022-11-22Merge 6.1-rc6 into tty-nextGreg Kroah-Hartman
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-18Merge tag 'tty-6.1-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver fixes from Greg KH: "Here are a number of small tty and serial driver fixes for 6.1-rc6. They all resolve reported problems: - kernel doc build problems with the -rc1 serial driver documentation update - n_gsm reported problems - imx serial driver missing callback - lots of tiny 8250 driver fixes for reported issues. All of these have been in linux-next for over a week with no reported problems" * tag 'tty-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: docs/driver-api/miscellaneous: Remove kernel-doc of serial_core.c serial: 8250: Flush DMA Rx on RLSI serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake serial: 8250_lpss: Configure DMA also w/o DMA filter serial: 8250: Fall back to non-DMA Rx if IIR_RDI occurs tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_send Revert "tty: n_gsm: replace kicktimer with delayed_work" Revert "tty: n_gsm: avoid call of sleeping functions from atomic context" serial: imx: Add missing .thaw_noirq hook tty: serial: fsl_lpuart: don't break the on-going transfer when global reset serial: 8250: omap: Flush PM QOS work on remove serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove() serial: 8250_omap: remove wait loop from Errata i202 workaround serial: 8250: omap: Fix missing PM runtime calls for omap8250_set_mctrl() serial: 8250: 8250_omap: Avoid RS485 RTS glitch on ->set_termios()
2022-11-09serial: 8250: Flush DMA Rx on RLSIIlpo Järvinen
Returning true from handle_rx_dma() without flushing DMA first creates a data ordering hazard. If DMA Rx has handled any character at the point when RLSI occurs, the non-DMA path handles any pending characters jumping them ahead of those characters that are pending under DMA. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: <stable@vger.kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250_lpss: Use 16B DMA burst with Elkhart LakeIlpo Järvinen
Configure DMA to use 16B burst size with Elkhart Lake. This makes the bus use more efficient and works around an issue which occurs with the previously used 1B. The fix was initially developed by Srikanth Thokala and Aman Kumar. This together with the previous config change is the cleaned up version of the original fix. Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake") Cc: <stable@vger.kernel.org> # serial: 8250_lpss: Configure DMA also w/o DMA filter Reported-by: Wentong Wu <wentong.wu@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250_lpss: Configure DMA also w/o DMA filterIlpo Järvinen
If the platform doesn't use DMA device filter (as is the case with Elkhart Lake), whole lpss8250_dma_setup() setup is skipped. This results in skipping also *_maxburst setup which is undesirable. Refactor lpss8250_dma_setup() to configure DMA even if filter is not setup. Cc: stable <stable@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250: Fall back to non-DMA Rx if IIR_RDI occursIlpo Järvinen
DW UART sometimes triggers IIR_RDI during DMA Rx when IIR_RX_TIMEOUT should have been triggered instead. Since IIR_RDI has higher priority than IIR_RX_TIMEOUT, this causes the Rx to hang into interrupt loop. The problem seems to occur at least with some combinations of small-sized transfers (I've reproduced the problem on Elkhart Lake PSE UARTs). If there's already an on-going Rx DMA and IIR_RDI triggers, fall graciously back to non-DMA Rx. That is, behave as if IIR_RX_TIMEOUT had occurred. 8250_omap already considers IIR_RDI similar to this change so its nothing unheard of. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: <stable@vger.kernel.org> Co-developed-by: Srikanth Thokala <srikanth.thokala@intel.com> Signed-off-by: Srikanth Thokala <srikanth.thokala@intel.com> Co-developed-by: Aman Kumar <aman.kumar@intel.com> Signed-off-by: Aman Kumar <aman.kumar@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250: 8250_omap: Fix calculation of RS485 delaysLukas Wunner
Commit 801954d1210a ("serial: 8250: 8250_omap: Support native RS485") calculates RS485 delays from the baudrate. The baudrate is generated with either a 16x or 13x divisor. The divisor is set in the Mode Definition Register 1 (MDR1). The commit erroneously assumes that the register stores the divisor as a bitmask and uses a logical AND to differentiate between 16x and 13x divisors. However the divisor is really stored as a 3-bit mode (see lines 363ff in include/uapi/linux/serial_reg.h). The logical AND operation is performed with UART_OMAP_MDR1_16X_MODE, which is defined as 0x0 and hence yields false. So the commit always assumes a 13x divisor. Fix by using an equal comparison. This works because we never set any of the other 5 bits in the register. (They pertain to IrDA mode, which is not supported by the driver). Fixes: 801954d1210a ("serial: 8250: 8250_omap: Support native RS485") Link: https://lore.kernel.org/linux-serial/202211070440.8hWunFUN-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/7d5b04da13d89b8708b9543a0b125f2b6062a77b.1667977259.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250_bcm7271: Fix error handling in brcmuart_init()Yuan Can
A problem about 8250_bcm7271 create debugfs failed is triggered with the following log given: [ 324.516635] debugfs: Directory 'bcm7271-uart' with parent '/' already present! The reason is that brcmuart_init() returns platform_driver_register() directly without checking its return value, if platform_driver_register() failed, it returns without destroy the newly created debugfs, resulting the debugfs of 8250_bcm7271 can never be created later. brcmuart_init() debugfs_create_dir() # create debugfs directory platform_driver_register() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without destroy debugfs directory Fix by removing debugfs when platform_driver_register() returns error. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Signed-off-by: Yuan Can <yuancan@huawei.com> Link: https://lore.kernel.org/r/20221109072110.117291-2-yuancan@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250_dma: Rearm DMA Rx if more data is pendingIlpo Järvinen
When DMA Rx completes, the current behavior is to just exit the DMA completion handler without future actions. If the transfer is still on-going, UART will trigger an interrupt and that eventually rearms the DMA Rx. The extra interrupt round-trip has an inherent latency cost that increases the risk of FIFO overrun. In such situations, the latency margin tends to already be less due to FIFO not being empty. Add check into DMA Rx completion handler to detect if LSR has DR (Data Ready) still set. DR indicates there will be more characters pending and DMA Rx can be rearmed right away to handle them. Cc: Gilles BULOZ <gilles.buloz@kontron.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221107102126.56481-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250_core: Use str_enabled_disabled() helperAndy Shevchenko
Use str_enabled_disabled() helper instead of open coding the same. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221017171633.65275-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: omap: Flush PM QOS work on removeTony Lindgren
Rebinding 8250_omap in a loop will at some point produce a warning for kernel/power/qos.c:296 cpu_latency_qos_update_request() with error "cpu_latency_qos_update_request called for unknown object". Let's flush the possibly pending PM QOS work scheduled from omap8250_runtime_suspend() before we disable runtime PM. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20221028110044.54719-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove()Tony Lindgren
On remove, we get an error for "Runtime PM usage count underflow!". I guess this driver is mostly built-in, and this issue has gone unnoticed for a while. Somehow I did not catch this issue with my earlier fix done with commit 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime"). Fixes: 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime") Signed-off-by: Tony Lindgren <tony@atomide.com> Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Link: https://lore.kernel.org/r/20221028105813.54290-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250_omap: remove wait loop from Errata i202 workaroundMatthias Schiffer
We were occasionally seeing the "Errata i202: timedout" on an AM335x board when repeatedly opening and closing a UART connected to an active sender. As new input may arrive at any time, it is possible to miss the "RX FIFO empty" condition, forcing the loop to wait until it times out. Nothing in the i202 Advisory states that such a wait is even necessary; other FIFO clear functions like serial8250_clear_fifos() do not wait either. For this reason, it seems safe to remove the wait, fixing the mentioned issue. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Link: https://lore.kernel.org/r/20221013112339.2540767-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: omap: Fix missing PM runtime calls for omap8250_set_mctrl()Tony Lindgren
There are cases where omap8250_set_mctrl() may get called after the UART has already autoidled causing an asynchronous external abort. This can happen on ttyport_open(): mem_serial_in from omap8250_set_mctrl+0x38/0xa0 omap8250_set_mctrl from uart_update_mctrl+0x4c/0x58 uart_update_mctrl from uart_dtr_rts+0x60/0xa8 uart_dtr_rts from tty_port_block_til_ready+0xd0/0x2a8 tty_port_block_til_ready from uart_open+0x14/0x1c uart_open from ttyport_open+0x64/0x148 And on ttyport_close(): omap8250_set_mctrl from uart_update_mctrl+0x3c/0x48 uart_update_mctrl from uart_dtr_rts+0x54/0x9c uart_dtr_rts from tty_port_shutdown+0x78/0x9c tty_port_shutdown from tty_port_close+0x3c/0x74 tty_port_close from ttyport_close+0x40/0x58 It can also happen on disassociate_ctty() calling uart_shutdown() that ends up calling omap8250_set_mctrl(). Let's fix the issue by adding missing PM runtime calls to omap8250_set_mctrl(). To do this, we need to add __omap8250_set_mctrl() that can be called from both omap8250_set_mctrl(), and from runtime PM resume path when restoring the registers. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Reported-by: Merlijn Wajer <merlijn@wizzup.org> Reported-by: Romain Naour <romain.naour@smile.fr> Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Link: https://lore.kernel.org/r/20221024063613.25943-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: 8250_omap: Avoid RS485 RTS glitch on ->set_termios()Lukas Wunner
RS485-enabled UART ports on TI Sitara SoCs with active-low polarity exhibit a Transmit Enable glitch on ->set_termios(): omap8250_restore_regs(), which is called from omap_8250_set_termios(), sets the TCRTLR bit in the MCR register and clears all other bits, including RTS. If RTS uses active-low polarity, it is now asserted for no reason. The TCRTLR bit is subsequently cleared by writing up->mcr to the MCR register. That variable is always zero, so the RTS bit is still cleared (incorrectly so if RTS is active-high). (up->mcr is not, as one might think, a cache of the MCR register's current value. Rather, it only caches a single bit of that register, the AFE bit. And it only does so if the UART supports the AFE bit, which OMAP does not. For details see serial8250_do_set_termios() and serial8250_do_set_mctrl().) Finally at the end of omap8250_restore_regs(), the MCR register is restored (and RTS deasserted) by a call to up->port.ops->set_mctrl() (which equals serial8250_set_mctrl()) and serial8250_em485_stop_tx(). So there's an RTS glitch between setting TCRTLR and calling serial8250_em485_stop_tx(). Avoid by using a read-modify-write when setting TCRTLR. While at it, drop a redundant initialization of up->mcr. As explained above, the variable isn't used by the driver and it is already initialized to zero because it is part of the static struct serial8250_ports[] declared in 8250_core.c. (Static structs are initialized to zero per section 6.7.8 nr. 10 of the C99 standard.) Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/6554b0241a2c7fd50f32576fdbafed96709e11e8.1664278942.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250/ingenic: Add support for the JZ4750/JZ4755Siarhei Volkau
JZ4750/55/60 (but not JZ4760b) have an optional /2 divider between the EXT oscillator and some peripherals including UART, which will be enabled if using a 24 MHz oscillator, and disabled when using a 12 MHz oscillator. This behavior relies on hardware differences: most boards (if not all) with those SoCs have 12 or 24 MHz oscillators but many peripherals want 12Mhz to operate properly (AIC and USB-PHY at least). The 16MHz threshold looks arbitrary but used in vendor's bootloader code for enable the divider. The patch doesn't affect JZ4760's behavior as it is subject for another patchset with re-classification of all supported ingenic UARTs. Link: https://github.com/carlos-wong/uboot_jz4755/blob/master/cpu/mips/jz_serial.c#L158 Signed-off-by: Siarhei Volkau <lis8215@gmail.com> Link: https://lore.kernel.org/r/20221031184041.1338129-3-lis8215@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: Use uart_xmit_advance()Ilpo Järvinen
Take advantage of the new uart_xmit_advance() helper. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250_bcm7271: Use uart_xmit_advance()Ilpo Järvinen
Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019091151.6692-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: 8250_omap: Support native RS485Lukas Wunner
Recent TI Sitara SoCs such as AM64/AM65 have gained the ability to automatically assert RTS when data is transmitted, obviating the need to emulate this functionality in software. The feature is controlled through new DIR_EN and DIR_POL bits in the Mode Definition Register 3. For details see page 8783 and 8890 of the AM65 TRM: https://www.ti.com/lit/ug/spruid7e/spruid7e.pdf Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Bin Liu <b-liu@ti.com> Tested-by: Zeng Chao <chao.zeng@siemens.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/e9f25f5c9200a35d3162973c2b45d6b892cc9bf2.1665906869.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21parisc/serial: Rename 8250_gsc.c to 8250_parisc.cHelge Deller
The file name of this driver is misleading - it handles various serial ports on parisc machines, not just such on the GSC bus. Rename the file to make this clearer. Suggested-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-21parisc: Make 8250_gsc driver dependend on CONFIG_PARISCHelge Deller
Although the name of the driver 8250_gsc.c suggests that it handles only serial ports on the GSC bus, it does handle serial ports listed in the parisc machine inventory as well, e.g. the serial ports in a C8000 PCI-only workstation. Change the dependency to CONFIG_PARISC, so that the driver gets included in the kernel even if CONFIG_GSC isn't set. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Helge Deller <deller@gmx.de>
2022-09-25serial: 8250: Fix restoring termios speed after suspendPali Rohár
Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Since commit 027b57170bf8 ("serial: core: Fix initializing and restoring termios speed") termios speed is available also in struct console. So properly restore also c_ispeed and c_ospeed members after suspend to fix restoring termios speed which is not represented by Bnnn constant. Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20220924104324.4035-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-25serial: Deassert Transmit Enable on probe in driver-specific wayLukas Wunner
When a UART port is newly registered, uart_configure_port() seeks to deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl. However a number of UART drivers interpret a set RTS bit as *assertion* instead of deassertion: Affected drivers include those using serial8250_em485_config() (except 8250_bcm2835aux.c) and some using mctrl_gpio (e.g. imx.c). Since the interpretation of the RTS bit is driver-specific, it is not suitable as a means to centrally deassert Transmit Enable in the serial core. Instead, the serial core must call on drivers to deassert it in their driver-specific way. One way to achieve that is to call ->rs485_config(). It implicitly deasserts Transmit Enable. So amend uart_configure_port() and uart_resume_port() to invoke uart_rs485_config(). That allows removing calls to uart_rs485_config() from drivers' ->probe() hooks and declaring the function static. Skip any invocation of ->set_mctrl() if RS485 is enabled. RS485 has no hardware flow control, so the modem control lines are irrelevant and need not be touched. When leaving RS485 mode, reset the modem control lines to the state stored in port->mctrl. That way, UARTs which are muxed between RS485 and RS232 transceivers drive the lines correctly when switched to RS232. (serial8250_do_startup() historically raises the OUT1 modem signal because otherwise interrupts are not signaled on ancient PC UARTs, but I believe that no longer applies to modern, RS485-capable UARTs and is thus safe to be skipped.) imx.c modifies port->mctrl whenever Transmit Enable is asserted and deasserted. Stop it from doing that so port->mctrl reflects the RS232 line state. 8250_omap.c deasserts Transmit Enable on ->runtime_resume() by calling ->set_mctrl(). Because that is now a no-op in RS485 mode, amend the function to call serial8250_em485_stop_tx(). fsl_lpuart.c retrieves and applies the RS485 device tree properties after registering the UART port. Because applying now happens on registration in uart_configure_port(), move retrieval of the properties ahead of uart_add_one_port(). Link: https://lore.kernel.org/all/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/ Link: https://lore.kernel.org/all/8f538a8903795f22f9acc94a9a31b03c9c4ccacb.camel@ginzinger.com/ Fixes: d3b3404df318 ("serial: Fix incorrect rs485 polarity on uart open") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reported-by: Roosen Henri <Henri.Roosen@ginzinger.com> Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-25serial: 8250_dma: Convert to use uart_xmit_advance()Andy Shevchenko
uart_xmit_advance() provides a common way on how to advance the Tx queue. Use it for the sake of unification and robustness. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220909091102.58941-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-25serial: 8250_omap: Convert to use uart_xmit_advance()Andy Shevchenko
uart_xmit_advance() provides a common way on how to advance the Tx queue. Use it for the sake of unification and robustness. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220909091258.68886-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-25Merge 7e2cd21e02b3 ("Merge tag 'tty-6.0-rc7' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next We need the tty fixes and api additions in this branch. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>