linux.git/drivers/usb/gadget/function/uvc_queue.c, branch v6.0

usb: gadget: uvc: calculate the number of request depending on framesize

2022-06-10T09:50:54+00:00

The current limitation of possible number of requests being handled is
dependent on the gadget speed. It makes more sense to depend on the
typical frame size when calculating the number of requests. This patch
is changing this and is using the previous limits as boundaries for
reasonable minimum and maximum number of requests.

For a 1080p jpeg encoded video stream with a maximum imagesize of
e.g. 800kB with a maxburst of 8 and an multiplier of 1 the resulting
number of requests is calculated to 49.

        800768         1
nreqs = ------ * -------------- ~= 49
          2      (1024 * 8 * 1)

Tested-by: Dan Vacura 
Signed-off-by: Michael Grzeschik 
Link: https://lore.kernel.org/r/20220529223848.105914-2-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Fix comment blocks style

2022-06-10T09:20:30+00:00

The UVC gadget 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.

Reviewed-by: Kieran Bingham 
Signed-off-by: Laurent Pinchart 
Link: https://lore.kernel.org/r/20220608174918.14656-1-laurent.pinchart@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman

Merge 5.18-rc5 into usb-next

2022-05-03T14:35:26+00:00

We need the USB fixes in here, and this resolves a merge issue in
drivers/usb/dwc3/drd.c

Reported-by: Stephen Rothwell 
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: giveback vb2 buffer on req complete

2022-04-21T16:15:33+00:00

On uvc_video_encode_isoc_sg the mapped vb2 buffer is returned
to early. Only after the last usb_request worked with the buffer
it is allowed to give it back to vb2. This patch fixes that.

Signed-off-by: Michael Grzeschik 
Link: https://lore.kernel.org/r/20220402232744.3622565-3-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: rework uvcg_queue_next_buffer to uvcg_complete_buffer

2022-04-21T16:15:33+00:00

The function uvcg_queue_next_buffer is used different than its name
suggests. The return value nextbuf is never used by any caller. This
patch reworks the function to its actual purpose, by removing the unused
code and renaming it. The function name uvcg_complete_buffer makes it
more clear that it is actually marking the current video buffer as
complete.

Signed-off-by: Michael Grzeschik 
Link: https://lore.kernel.org/r/20220402232744.3622565-2-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: remove pause flag use

2022-04-21T16:15:07+00:00

The pause flag doesn't appear to serve a purpose as it is possible for
the pump worker thread to not be running when new buffers are queued.
Before the following change was introduced: "43cd0023872e usb: gadget:
uvc_video: add worker to handle the frame pumping", the pause flag
status was discarded and never returned. This masked a current issues of
the userspace receiving non-zero values (considered unsuccessful) and
prevents trace_v4l2_qbuf() from being called.

Signed-off-by: Dan Vacura 
Link: https://lore.kernel.org/r/20220413192402.26063-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: Fix crash when encoding data for usb request

2022-04-19T14:22:20+00:00

During the uvcg_video_pump() process, if an error occurs and
uvcg_queue_cancel() is called, the buffer queue will be cleared out, but
the current marker (queue->buf_used) of the active buffer (no longer
active) is not reset. On the next iteration of uvcg_video_pump() the
stale buf_used count will be used and the logic of min((unsigned
int)len, buf->bytesused - queue->buf_used) may incorrectly calculate a
nbytes size, causing an invalid memory access.

[80802.185460][  T315] configfs-gadget gadget: uvc: VS request completed
with status -18.
[80802.185519][  T315] configfs-gadget gadget: uvc: VS request completed
with status -18.
...
uvcg_queue_cancel() is called and the queue is cleared out, but the
marker queue->buf_used is not reset.
...
[80802.262328][ T8682] Unable to handle kernel paging request at virtual
address ffffffc03af9f000
...
...
[80802.263138][ T8682] Call trace:
[80802.263146][ T8682]  __memcpy+0x12c/0x180
[80802.263155][ T8682]  uvcg_video_pump+0xcc/0x1e0
[80802.263165][ T8682]  process_one_work+0x2cc/0x568
[80802.263173][ T8682]  worker_thread+0x28c/0x518
[80802.263181][ T8682]  kthread+0x160/0x170
[80802.263188][ T8682]  ret_from_fork+0x10/0x18
[80802.263198][ T8682] Code: a8c12829 a88130cb a8c130

Fixes: d692522577c0 ("usb: gadget/uvc: Port UVC webcam gadget to use videobuf2 framework")
Cc: 
Signed-off-by: Dan Vacura 
Link: https://lore.kernel.org/r/20220331184024.23918-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: implement dwPresentationTime and scrSourceClock

2021-10-25T07:20:08+00:00

This patch adds the fields UVC_STREAM_PTS and UVC_STREAM_SCR to the uvc
header, in case this data is available. It also enables the copy of the
timestamp to the vb2_v4l2_buffer by setting V4L2_BUF_FLAG_TIMESTAMP_COPY
in the queue.timestamp_flags.

Signed-off-by: Michael Olbrich 
Signed-off-by: Michael Grzeschik 
Link: https://lore.kernel.org/r/20211022093223.26493-2-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: add scatter gather support

2021-07-27T13:59:19+00:00

This patch adds support for scatter gather transfers. If the underlying
gadgets sg_supported == true, then the videeobuf2-dma-sg is used and the
encode routine maps all scatter entries to separate scatterlists for the
usb gadget.

When streaming 1080p with request size of 1024 times 3 bytes top shows a
difference of about 6.4% CPU load applying this patch:

 PID USER      PR  NI    VIRT    RES  %CPU  %MEM     TIME+ S COMMAND

  64 root       0 -20    0.0m   0.0m   7.7   0.0   0:01.25 I [kworker/u5:0-uvcvideo]
  83 root       0 -20    0.0m   0.0m   4.5   0.0   0:03.71 I [kworker/u5:3-uvcvideo]
 307 root     -51   0    0.0m   0.0m   3.8   0.0   0:01.05 S [irq/51-dwc3]

vs.

  64 root       0 -20    0.0m   0.0m   5.8   0.0   0:01.79 I [kworker/u5:0-uvcvideo]
 306 root     -51   0    0.0m   0.0m   3.2   0.0   0:01.97 S [irq/51-dwc3]
  82 root       0 -20    0.0m   0.0m   0.6   0.0   0:01.86 I [kworker/u5:1-uvcvideo]

Signed-off-by: Michael Grzeschik 
Link: https://lore.kernel.org/r/20210628155311.16762-5-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

usb: gadget: uvc: make uvc_num_requests depend on gadget speed

2021-07-27T13:59:18+00:00

While sending bigger images is possible with USB_SPEED_SUPER it is
better to use more isochronous requests in flight. This patch makes the
number uvc_num_requests dynamic by changing it depending on the gadget
speed.

Reviewed-by: Paul Elder 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Michael Grzeschik 
Link: https://lore.kernel.org/r/20210628155311.16762-3-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman