[PATCH v7 0/9] usb: gadget: uvc: effectively fill the udc isoc pipeline with available video buffers and fixes

[Michael Grzeschik <m.grzeschik@pengutronix.de>]

This patch series is improving the size calculation and allocation of
the uvc requests. Using the selected frame duration of the stream it is
possible to calculate the number of requests based on the interval
length.

It also precalculates the request length based on the actual per frame
size for compressed formats.

For this calculations to work it was needed to rework the request
queueing by moving the encoding to one extra thread (in this case we
chose the qbuf) context.

Next it was needed to move the actual request enqueueing to one extra
thread which is kept busy to fill the isoc queue in the udc.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
Changes in v7:
- fixed build of tracing in uvc_trace
- Link to v6: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v6-0-08c05522e1f5@pengutronix.de

Changes in v6:
- fixes in: ("usb: gadget: uvc: add trace of enqueued and completed requests")
- Link to v5: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v5-0-2de78794365c@pengutronix.de

Changes in v5:
- dropped: ('usb: gadget: uvc: remove pump worker and enqueue all buffers per frame in qbuf')
- squashed ('usb: gadget: uvc: rework to enqueue in pump worker from encoded queue') and ('usb: gadget: uvc: remove uvc_video_ep_queue_initial_requests'))
- squashed ('usb: gadget: uvc: set req_size once when the vb2 queue is calculated') and ('usb: gadget: uvc: set req_size and n_requests based on the frame interval')
- replaced ('usb: gadget: uvc: add min g_ctrl vidioc and set min buffs to 4') with ('usb: gadget: uvc: set nbuffers to minimum STREAMING_MIN_BUFFERS in uvc_queue_setup')
- added ('usb: gadget: uvc: wake pump everytime we update the free list')
- added ('usb: gadget: uvc: add trace of enqueued and completed requests')
- added ('usb: gadget: uvc: dont call usb_composite_setup_continue when not streamin')
- some patch reordering
- Link to v4: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v4-0-ca22f334226e@pengutronix.de

Changes in v4:
- fixed exit path in uvc_enqueue_buffer on loop break
- Link to v3: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v3-0-4da7033dd488@pengutronix.de

Changes in v3:
- Added more patches necessary to properly rework the request queueing
- Link to v2: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v2-0-12690f7a2eff@pengutronix.de

Changes in v2:
- added header size into calculation of request size
- Link to v1: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v1-0-9436c4716233@pengutronix.de

---
Michael Grzeschik (9):
      usb: gadget: uvc: wake pump everytime we update the free list
      usb: gadget: uvc: only enqueue zero length requests in potential underrun
      usb: gadget: uvc: rework to enqueue in pump worker from encoded queue
      usb: gadget: uvc: add g_parm and s_parm for frame interval
      usb: gadget: uvc: set req_size and n_requests based on the frame interval
      usb: gadget: uvc: set req_length based on payload by nreqs instead of req_size
      usb: gadget: uvc: set nbuffers to minimum STREAMING_MIN_BUFFERS in uvc_queue_setup
      usb: gadget: uvc: add trace of enqueued and completed requests
      usb: gadget: uvc: dont call usb_composite_setup_continue when not streaming

 drivers/usb/gadget/function/Makefile    |   4 +
 drivers/usb/gadget/function/f_uvc.c     |   2 +
 drivers/usb/gadget/function/uvc.h       |  13 ++
 drivers/usb/gadget/function/uvc_queue.c |  26 ++--
 drivers/usb/gadget/function/uvc_queue.h |   2 +
 drivers/usb/gadget/function/uvc_trace.c |  11 ++
 drivers/usb/gadget/function/uvc_trace.h |  60 ++++++++
 drivers/usb/gadget/function/uvc_v4l2.c  |  55 +++++++
 drivers/usb/gadget/function/uvc_video.c | 264 +++++++++++++++++++-------------
 9 files changed, 317 insertions(+), 120 deletions(-)
---
base-commit: 64f3b5a6bc49adf77d58eddd72a4bfccd492fa24
change-id: 20240403-uvc_request_length_by_interval-a7efd587d963

Best regards,
-- 
Michael Grzeschik <m.grzeschik@pengutronix.de>