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path: root/drivers/media/usb/uvc/uvc_status.c
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2023-01-15media: uvcvideo: Fix race condition with usb_kill_urbRicardo Ribalda1-0/+37
usb_kill_urb warranties that all the handlers are finished when it returns, but does not protect against threads that might be handling asynchronously the urb. For UVC, the function uvc_ctrl_status_event_async() takes care of control changes asynchronously. If the code is executed in the following order: CPU 0 CPU 1 ===== ===== uvc_status_complete() uvc_status_stop() uvc_ctrl_status_event_work() uvc_status_start() -> FAIL Then uvc_status_start will keep failing and this error will be shown: <4>[ 5.540139] URB 0000000000000000 submitted while active drivers/usb/core/urb.c:378 usb_submit_urb+0x4c3/0x528 Let's improve the current situation, by not re-submiting the urb if we are stopping the status event. Also process the queued work (if any) during stop. CPU 0 CPU 1 ===== ===== uvc_status_complete() uvc_status_stop() uvc_status_start() uvc_ctrl_status_event_work() -> FAIL Hopefully, with the usb layer protection this should be enough to cover all the cases. Cc: stable@vger.kernel.org Fixes: e5225c820c05 ("media: uvcvideo: Send a control event when a Control Change interrupt arrives") Reviewed-by: Yunke Cao <yunkec@chromium.org> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2023-01-15media: uvcvideo: Remove void casting for the status endpointRicardo Ribalda1-43/+22
Make the code more resilient, by replacing the castings with proper structure definitions and using offsetof() instead of open coding the location of the data. Suggested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2023-01-15media: uvcvideo: Only create input devs if hw supports itRicardo Ribalda1-0/+23
Examine the stream headers to figure out if the device has a button and can be used as an input. Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2022-07-16media: uvcvideo: Fix comment blocks styleLaurent Pinchart1-3/+3
The uvcvideo driver historically uses the /* Comment * style */ for multi-line block comments, which is frowned upon. Patches for the driver are required to use the more standard /* * Comment * style */ style. This result in inconsistencies. Fix it by converting all remaining instances of the old style. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Reviewed-by: Ricardo Ribalda <ribalda@chromium.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
2021-01-27media: uvcvideo: Rename debug functionsJoe Perches1-16/+13
trace isn't a good name as it's not a trace mechanism, it is a typical debug mechanism. Rename uvc_trace/uvc_trace_cont macros to uvc_dbg/uvc_dbg_cont. Rename uvc_trace_param to uvc_dbg_param Rename UVC_TRACE_<FOO> defines to UVC_DBG_<FOO> Use ## concatenation in uvc_dbg macros to avoid overly long and repetitive UVC_DBG uses Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-01-27media: uvcvideo: use dev_printk() for uvc_trace()Ricardo Ribalda1-9/+10
Instead of calling prink() inside uvc_trace, use dev_printk(), which adds context to the output. Now that we are at it, regroup the strings so the messages can be easily "grepable". Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-01-27media: uvcvideo: Use dev_ printk aliasesRicardo Ribalda1-6/+7
Replace all the uses of printk() and uvc_printk() with its equivalent dev_ alias macros. Modify uvc_warn_once() macro to use dev_info instead printk(). They are more standard across the kernel tree and provide more context about the error. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-01-27media: uvcvideo: Provide sync and async uvc_ctrl_status_eventRicardo Ribalda1-1/+2
Split the functionality of void uvc_ctrl_status_event_work in two, so it can be called by functions outside interrupt context and not part of an URB. Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-6/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-03media: uvcvideo: Refactor teardown of uvc on USB disconnectDaniel Axtens1-4/+8
Currently, disconnecting a USB webcam while it is in use prints out a number of warnings, such as: WARNING: CPU: 2 PID: 3118 at /build/linux-ezBi1T/linux-4.8.0/fs/sysfs/group.c:237 sysfs_remove_group+0x8b/0x90 sysfs group ffffffffa7cd0780 not found for kobject 'event13' This has been noticed before. [0] This is because of the order in which things are torn down. If there are no streams active during a USB disconnect: - uvc_disconnect() is invoked via device_del() through the bus notifier mechanism. - this calls uvc_unregister_video(). - uvc_unregister_video() unregisters the video device for each stream, - because there are no streams open, it calls uvc_delete() - uvc_delete() calls uvc_status_cleanup(), which cleans up the status input device. - uvc_delete() calls media_device_unregister(), which cleans up the media device - uvc_delete(), uvc_unregister_video() and uvc_disconnect() all return, and we end up back in device_del(). - device_del() then cleans up the sysfs folder for the camera with dpm_sysfs_remove(). Because uvc_status_cleanup() and media_device_unregister() have already been called, this all works nicely. If, on the other hand, there *are* streams active during a USB disconnect: - uvc_disconnect() is invoked - this calls uvc_unregister_video() - uvc_unregister_video() unregisters the video device for each stream, - uvc_unregister_video() and uvc_disconnect() return, and we end up back in device_del(). - device_del() then cleans up the sysfs folder for the camera with dpm_sysfs_remove(). Because the status input device and the media device are children of the USB device, this also deletes their sysfs folders. - Sometime later, the final stream is closed, invoking uvc_release(). - uvc_release() calls uvc_delete() - uvc_delete() calls uvc_status_cleanup(), which cleans up the status input device. Because the sysfs directory has already been removed, this causes a WARNing. - uvc_delete() calls media_device_unregister(), which cleans up the media device. Because the sysfs directory has already been removed, this causes another WARNing. To fix this, we need to make sure the devices are always unregistered before the end of uvc_disconnect(). To this, move the unregistration into the disconnect path: - split uvc_status_cleanup() into two parts, one on disconnect that unregisters and one on delete that frees. - move v4l2_device_unregister() and media_device_unregister() into the disconnect path. [0]: https://lkml.org/lkml/2016/12/8/657 [Renamed uvc_input_cleanup() to uvc_input_unregister()] Signed-off-by: Daniel Axtens <dja@axtens.net> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-07-27media: uvcvideo: Send a control event when a Control Change interrupt arrivesGuennadi Liakhovetski1-14/+107
UVC defines a method of handling asynchronous controls, which sends a USB packet over the interrupt pipe. This patch implements support for such packets by sending a control event to the user. Since this can involve USB traffic and, therefore, scheduling, this has to be done in a work queue. Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-02-23media: uvcvideo: Use internal kernel integer typesLaurent Pinchart1-2/+2
Replace the __[su]{8,16,32} variant of integer types with the non-underscored types as the code is internal to the driver, not exposed to userspace. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-12-08media: uvcvideo: Stream error events carry no dataLaurent Pinchart1-2/+3
According to the UVC specification, stream error events carry no data. Fix a buffer overflow (that should be harmless given data alignment) when reporting the stream error event by removing the data byte from the message. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2013-06-08[media] uvcvideo: Fix open/close race conditionLaurent Pinchart1-19/+2
Maintaining the users count using an atomic variable makes sure that access to the counter won't be racy, but doesn't serialize access to the operations protected by the counter. This creates a race condition that could result in the status URB being submitted multiple times. Use a mutex to protect the users count and serialize access to the status start and stop operations. Reported-by: Shawn Nematbakhsh <shawnn@chromium.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-08-15[media] rename most media/video usb drivers to media/usbMauro Carvalho Chehab1-0/+237
Rename all USB drivers with their own directory under drivers/media/video into drivers/media/usb and update the building system. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>