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path: root/drivers/usb/host/xhci-dbgcap.h
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2025-05-05xhci: dbc: Avoid event polling busyloop if pending rx transfers are inactive.Mathias Nyman
Event polling delay is set to 0 if there are any pending requests in either rx or tx requests lists. Checking for pending requests does not work well for "IN" transfers as the tty driver always queues requests to the list and TRBs to the ring, preparing to receive data from the host. This causes unnecessary busylooping and cpu hogging. Only set the event polling delay to 0 if there are pending tx "write" transfers, or if it was less than 10ms since last active data transfer in any direction. Cc: Łukasz Bartosik <ukaszb@chromium.org> Fixes: fb18e5bb9660 ("xhci: dbc: poll at different rate depending on data transfer activity") Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250505125630.561699-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-17xhci: dbc: honor usb transfer size boundaries.Mathias Nyman
Treat each completed full size write to /dev/ttyDBC0 as a separate usb transfer. Make sure the size of the TRBs matches the size of the tty write by first queuing as many max packet size TRBs as possible up to the last TRB which will be cut short to match the size of the tty write. This solves an issue where userspace writes several transfers back to back via /dev/ttyDBC0 into a kfifo before dbgtty can find available request to turn that kfifo data into TRBs on the transfer ring. The boundary between transfer was lost as xhci-dbgtty then turned everyting in the kfifo into as many 'max packet size' TRBs as possible. DbC would then send more data to the host than intended for that transfer, causing host to issue a babble error. Refuse to write more data to kfifo until previous tty write data is turned into properly sized TRBs with data size boundaries matching tty write size Tested-by: Uday M Bhat <uday.m.bhat@intel.com> Tested-by: Łukasz Bartosik <ukaszb@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241016140000.783905-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 ...
2024-09-05xhci: dbc: Fix STALL transfer event handlingMathias Nyman
Don't flush all pending DbC data requests when an endpoint halts. An endpoint may halt and xHC DbC triggers a STALL error event if there's an issue with a bulk data transfer. The transfer should restart once xHC DbC receives a ClearFeature(ENDPOINT_HALT) request from the host. Once xHC DbC restarts it will start from the TRB pointed to by dequeue field in the endpoint context, which might be the same TRB we got the STALL event for. Turn the TRB to a no-op in this case to make sure xHC DbC doesn't reuse and tries to retransmit this same TRB after we already handled it, and gave its corresponding data request back. Other STALL events might be completely bogus. Lukasz Bartosik discovered that xHC DbC might issue spurious STALL events if hosts sends a ClearFeature(ENDPOINT_HALT) request to non-halted endpoints even without any active bulk transfers. Assume STALL event is spurious if it reports 0 bytes transferred, and the endpoint stopped on the STALLED TRB. Don't give back the data request corresponding to the TRB in this case. The halted status is per endpoint. Track it with a per endpoint flag instead of the driver invented DbC wide DS_STALLED state. DbC remains in DbC-Configured state even if endpoints halt. There is no Stalled state in the DbC Port state Machine (xhci section 7.6.6) Reported-by: Łukasz Bartosik <ukaszb@chromium.org> Closes: https://lore.kernel.org/linux-usb/20240725074857.623299-1-ukaszb@chromium.org/ Tested-by: Łukasz Bartosik <ukaszb@chromium.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20240905143300.1959279-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-14xhci: dbgtty: use kfifo from tty_port structJiri Slaby (SUSE)
There is no need to define one in a custom structure. The tty_port one is free to use. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-usb@vger.kernel.org Link: https://lore.kernel.org/r/20240808103549.429349-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-27xhci: dbc: Allow users to modify DbC poll interval via sysfsUday M Bhat
xhci DbC driver polls the host controller for DbC events at a reduced rate when DbC is enabled but there are no active data transfers. Allow users to modify this reduced poll interval via dbc_poll_interval_ms sysfs entry. Unit is milliseconds and accepted range is 0 to 5000. Max interval of 5000 ms is selected as it matches the common 5 second timeout used in usb stack. Default value is 64 milliseconds. A long interval is useful when users know there won't be any activity on systems connected via DbC for long periods, and want to avoid battery drainage due to unnecessary CPU usage. Example being Android Debugger (ADB) usage over DbC on ChromeOS systems running Android Runtime. [minor changes and rewording -Mathias] Co-developed-by: Samuel Jacob <samjaco@google.com> Signed-off-by: Samuel Jacob <samjaco@google.com> Signed-off-by: Uday M Bhat <uday.m.bhat@intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20240626124835.1023046-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-02xhci: dbc: poll at different rate depending on data transfer activityMathias Nyman
DbC driver starts polling for events immediately when DbC is enabled. The current polling interval is 1ms, which keeps the CPU busy, impacting power management even when there are no active data transfers. Solve this by polling at a slower rate, with a 64ms interval as default until a transfer request is queued, or if there are still are pending unhandled transfers at event completion. Tested-by: Uday M Bhat <uday.m.bhat@intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20240229141438.619372-9-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-04xhci: dbc: Use sysfs_emit() to instead of scnprintf()Andy Shevchenko
Follow the advice of the Documentation/filesystems/sysfs.rst and show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20231201150647.1307406-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-23xhci: dbc: Provide sysfs option to configure dbc descriptorsMathias Nyman
When DbC is enabled the first port on the xHC host acts as a usb device. xHC provides the descriptors automatically when the DbC device is enumerated. Most of the values are hardcoded, but some fields such as idProduct, idVendor, bcdDevice and bInterfaceProtocol can be modified. Add sysfs entries that allow userspace to change these. User can only change them before dbc is enabled, i.e. before writing "enable" to dbc sysfs file as we don't want these values to change while device is connected, or during enumeration. Add documentation for these entries in Documentation/ABI/testing/sysfs-bus-pci-drivers-xhci_hcd Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20230317154715.535523-9-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-17xhci: dbgtty: use IDR to support several dbc instances.Mathias Nyman
To support systems with several xhci controllers with active dbc on each xhci we need to use IDR to identify and give an index to each port. Avoid using global struct tty_driver.driver_state for storing dbc port pointer as it won't work with several dbc ports Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20220216095153.1303105-6-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-17xhci: dbc: Don't call dbc_tty_init() on every dbc tty probeMathias Nyman
The current workaround to call the dbc_tty_init() in probe is not working in case we have several xhci devices with dbc enabled. dbc_tty_init() should be called only once by a module init call when module is loaded. until dbgtty is its own module call dbc_tty_init() from xhci module init call. Same is true for unloading and dbc_tty_exit() Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20220216095153.1303105-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-17xhci: dbc: Rename xhci_dbc_init and xhci_dbc_exitMathias Nyman
These names give the impression the functions are related to module init calls, but are in fact creating and removing the dbc fake device Rename them to xhci_create_dbc_dev() and xhci_remove_dbc_dev(). We will need the _init and _exit names for actual dbc module init and exit calls. No functional changes Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20220216095153.1303105-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-17xhci: dbc: create and remove dbc structure in dbgtty driver.Mathias Nyman
Turn the dbgtty closer to a device driver by allocating the dbc structure in its own xhci_dbc_tty_probe() function, and freeing it in xhci_dbc_tty_remove() Remove xhci_do_dbc_exit() as its no longer needed. allocate and create the dbc strcuture in xhci_dbc_tty_probe() Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20220216095153.1303105-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: remove tty specific port structure from struct xhci_dbcMathias Nyman
Use a void pointer that any function driver can use instead. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-28-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: Add a operations structure to access driver functionsMathias Nyman
Don't call dbctty driver functions directly from dbc core code. Introduce a new dbc_driver structure that contains function pointers for disconnect and configure operations. The driver (ttydbc) must provide these opeations when creating a dbc. Name the structure dbc_driver instead of dbc_ops as we plan to add more driver configureable values here, such as vid and pid. Decouples dbc and dbctty. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-26-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbctty: split dbc tty driver registration and unregistration functions.Mathias Nyman
Split the dbc tty driver registrations function into separate init and probe parts. The init part will register the tty driver, and should in the future be called from module_init(). The probe part will become the normal probe function, but for now it is called from the init part. The unregister function is s likewise split into remove and exit parts. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-25-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: remove endpoint pointers from dbc_port structureMathias Nyman
dbctty no longer needs references directly to dbc endpoints, so remove them Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-24-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: simplify dbc requests allocation and queueingMathias Nyman
Don't pass endpoint pointer, dbctty should not be aware of struct dbc_ep, knowing the direction is enough. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-23-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: Use dbc structure in the request completion instead of xhci_hcdMathias Nyman
The dbc request completion callback doesn't need a xhci_hcd pointer. The only user of the xhci_hcd pointer in dbgtty request callback was the xhci_warn() function. Change it to dev_warn() instead. While changing the callback function parameter to dbc in struct xhci_requeset, move the struct xhci_request declaraion down a bit in the header file to avoid compiler warinings No functional changes This change helps decoupling xhci and DbC Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-18-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: Pass dbc pointer to get_in/out_ep() helper functions to get endpointsMathias Nyman
Pass dbc pointer instead of struct xhci_hcd pointer to the get_in_ep() and get_out_ep() helper functions. No functional changes This change helps decoupling xhci and DbC Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-17-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbgtty: Pass dbc pointer when registering a dbctty deviceMathias Nyman
Pass dbc pointer to the xhci_dbc_tty_register_device() and xhci_dbc_tty_unregister_device() functions instead of xhci_hcd pointer These functions don't need a xhci_hcd pointer anymore, only use case was the xhci_err() function, which is now changed to a dev_err() instead. No functional changes This change helps decoupling xhci and DbC Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-16-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23xhci: dbc: Add device pointer to dbc structureMathias Nyman
Currently the dbc structure contains a pointer to struct xhci_hcd, and dbc functions use that to dig up the underlying device pointer. We are trying to decouple xhci and dbc code, and prepare for code that use dbc such as dbctty into into real device drivers. This is one step along the way. Keep functionality the same and keep the xhci pointer, and let the new device pointer point to the xhci device for now. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200723144530.9992-8-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-24usb: xhci: dbc: Add SPDX identifiers to dbc filesLu Baolu
Update the xhci dbc files with the correct SPDX license identifiers. Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver") Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Philippe Ombredanne <pombredanne@nexB.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-08usb: xhci: Add DbC support in xHCI driverLu Baolu
xHCI compatible USB host controllers(i.e. super-speed USB3 controllers) can be implemented with the Debug Capability(DbC). It presents a debug device which is fully compliant with the USB framework and provides the equivalent of a very high performance full-duplex serial link. The debug capability operation model and registers interface are defined in 7.6.8 of the xHCI specification, revision 1.1. The DbC debug device shares a root port with the xHCI host. By default, the debug capability is disabled and the root port is assigned to xHCI. When the DbC is enabled, the root port will be assigned to the DbC debug device, and the xHCI sees nothing on this port. This implementation uses a sysfs node named <dbc> under the xHCI device to manage the enabling and disabling of the debug capability. When the debug capability is enabled, it will present a debug device through the debug port. This debug device is fully compliant with the USB3 framework, and it can be enumerated by a debug host on the other end of the USB link. As soon as the debug device is configured, a TTY serial device named /dev/ttyDBC0 will be created. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>