kernel/linux.git/drivers/usb/gadget/function/uvc.h, branch v6.12.80

usb:gadget:uvc Do not use worker thread to pump isoc usb requests

2023-11-23T12:32:44+00:00

When we use an async work queue to perform the function of pumping usb requests to the usb controller, it is possible that amongst other factors, thread scheduling affects at what cadence we're able to pump requests. This could mean isoc usb requests miss their uframes - resulting in video stream flickers on the host device. To avoid this, we make the async_wq thread only produce isoc usb_requests with uvc buffers encoded into them. The process of queueing to the endpoint is done by the uvc_video_complete() handler. In case no usb_requests are ready with encoded information, we just queue a zero length request to the endpoint from the complete handler. For bulk endpoints the async_wq thread still queues usb requests to the endpoint. Signed-off-by: Michael Grzeschik Signed-off-by: Jayant Chowdhary Suggested-by: Avichal Rakesh Suggested-by: Alan Stern Link: https://lore.kernel.org/r/20231120062026.3759463-1-jchowdhary@google.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Fix use-after-free for inflight usb_requests

2023-11-23T12:32:44+00:00

Currently, the uvc gadget driver allocates all uvc_requests as one array and deallocates them all when the video stream stops. This includes de-allocating all the usb_requests associated with those uvc_requests. This can lead to use-after-free issues if any of those de-allocated usb_requests were still owned by the usb controller. This is patch 2 of 2 in fixing the use-after-free issue. It adds a new flag to uvc_video to track when frames and requests should be flowing. When disabling the video stream, the flag is tripped and, instead of de-allocating all uvc_requests and usb_requests, the gadget driver only de-allocates those usb_requests that are currently owned by it (as present in req_free). Other usb_requests are left untouched until their completion handler is called which takes care of freeing the usb_request and its corresponding uvc_request. Now that uvc_video does not depends on uvc->state, this patch removes unnecessary upates to uvc->state that were made to accommodate uvc_video logic. This should ensure that uvc gadget driver never accidentally de-allocates a usb_request that it doesn't own. Link: https://lore.kernel.org/7cd81649-2795-45b6-8c10-b7df1055020d@google.com Reviewed-by: Daniel Scally Reviewed-by: Michael Grzeschik Suggested-by: Michael Grzeschik Tested-by: Michael Grzeschik Signed-off-by: Avichal Rakesh Link: https://lore.kernel.org/r/20231109004104.3467968-4-arakesh@google.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Allocate uvc_requests one at a time

2023-11-23T12:32:44+00:00

Currently, the uvc gadget driver allocates all uvc_requests as one array and deallocates them all when the video stream stops. This includes de-allocating all the usb_requests associated with those uvc_requests. This can lead to use-after-free issues if any of those de-allocated usb_requests were still owned by the usb controller. This patch is 1 of 2 patches addressing the use-after-free issue. Instead of bulk allocating all uvc_requests as an array, this patch allocates uvc_requests one at a time, which should allows for similar granularity when deallocating the uvc_requests. This patch has no functional changes other than allocating each uvc_request separately, and similarly freeing each of them separately. Link: https://lore.kernel.org/7cd81649-2795-45b6-8c10-b7df1055020d@google.com Reviewed-by: Daniel Scally Reviewed-by: Michael Grzeschik Suggested-by: Michael Grzeschik Tested-by: Michael Grzeschik Signed-off-by: Avichal Rakesh Link: https://lore.kernel.org/r/20231109004104.3467968-2-arakesh@google.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: prevent use of disabled endpoint

2023-11-23T12:32:44+00:00

Currently the set_alt callback immediately disables the endpoint and queues the v4l2 streamoff event. However, as the streamoff event is processed asynchronously, it is possible that the video_pump thread attempts to queue requests to an already disabled endpoint. This change moves disabling usb endpoint to the end of streamoff event callback. As the endpoint's state can no longer be used, video_pump is now guarded by uvc->state as well. To be consistent with the actual streaming state, uvc->state is now toggled between CONNECTED and STREAMING from the v4l2 event callback only. Link: https://lore.kernel.org/20230615171558.GK741@pendragon.ideasonboard.com/ Link: https://lore.kernel.org/20230531085544.253363-1-dan.scally@ideasonboard.com/ Reviewed-by: Daniel Scally Reviewed-by: Michael Grzeschik Tested-by: Michael Grzeschik Signed-off-by: Avichal Rakesh Link: https://lore.kernel.org/r/20231109004104.3467968-1-arakesh@google.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: function: Remove unused declarations

2023-08-22T12:45:29+00:00

These declarations are not implemented anymore, remove them. Signed-off-by: Yue Haibing Link: https://lore.kernel.org/r/20230818124025.51576-1-yuehaibing@huawei.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Copy XU descriptors during .bind()

2023-02-07T07:46:36+00:00

Now that extension unit support is available through configfs we need to copy the descriptors for the XUs during uvc_function_bind() so that they're exposed to the usb subsystem. Reviewed-by: Laurent Pinchart Signed-off-by: Daniel Scally Link: https://lore.kernel.org/r/20230206161802.892954-5-dan.scally@ideasonboard.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Disable interrupt endpoint by default

2023-02-02T10:16:17+00:00

The f_uvc code includes an interrupt endpoint against the VideoControl interface. According to section 2.4.2 of the UVC specification however this endpoint is optional in at least some cases: "This endpoint is optional, but may be mandatory under certain conditions" The conditions enumerated are whether... 1. The device supports hardware triggers 2. The device implements any AutoUpdate controls 3. The device implements any Asynchronous controls As all of those things are implementation dependent, this endpoint might be unnecessary for some users. Further to that it is unusable in the current implementation as there is no mechanism within the UVC gadget driver that allows data to be sent over that endpoint. Disable the interrupt endpoint by default, but check whether the user has asked for it to be enabled in configfs and continue to generate it if so. Signed-off-by: Daniel Scally Link: https://lore.kernel.org/r/20230130105045.120886-4-dan.scally@ideasonboard.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Rename uvc_control_ep

2023-02-02T10:16:17+00:00

The f_uvc code defines an endpoint named "uvc_control_ep" but it is configured with a non-zero endpoint address and has its bmAttributes flagged as USB_ENDPOINT_XFER_INT - this cannot be the VideoControl interface's control endpoint, as the default endpoint 0 is used for that purpose. This is instead the optional interrupt endpoint that can be contained by a VideoControl interface. There is also a Class-specific VC Interrupt Endpoint Descriptor and a SuperSpeed companion descriptor that are also for the VC interface's interrupt endpoint but are named as though they are for the control endpoint. Rename the variables to make that clear. Signed-off-by: Daniel Scally Link: https://lore.kernel.org/r/20230130105045.120886-2-dan.scally@ideasonboard.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: add v4l2 enumeration api calls

2022-09-22T13:52:30+00:00

This patch adds support to the v4l2 VIDIOCs for enum_format, enum_framesizes and enum_frameintervals. This way, the userspace application can use these VIDIOCS to query the via configfs exported frame capabilities. With thes callbacks the userspace doesn't have to bring its own configfs parser. Signed-off-by: Michael Grzeschik Link: https://lore.kernel.org/r/20220909221335.15033-4-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: increase worker prio to WQ_HIGHPRI

2022-09-09T07:30:18+00:00

This patch is changing the simple workqueue in the gadget driver to be allocated as async_wq with a higher priority. The pump worker, that is filling the usb requests, will have a higher priority and will not be scheduled away so often while the video stream is handled. This will lead to fewer streaming underruns. Signed-off-by: Michael Grzeschik Link: https://lore.kernel.org/r/20220907215818.2670097-1-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman