media: uvcvideo: Move decode processing to process context
Newer high definition cameras, and cameras with multiple lenses such as
the range of stereo-vision cameras now available have ever increasing
data rates.
The inclusion of a variable length packet header in URB packets mean
that we must memcpy the frame data out to our destination 'manually'.
This can result in data rates of up to 2 gigabits per second being
processed.
To improve efficiency, and maximise throughput, handle the URB decode
processing through a work queue to move it from interrupt context, and
allow multiple processors to work on URBs in parallel.
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
---
v2:
- Lock full critical section of usb_submit_urb()
v3:
- Fix race on submitting uvc_video_decode_data_work() to work queue.
- Rename uvc_decode_op -> uvc_copy_op (Generic to encode/decode)
- Rename decodes -> copy_operations
- Don't queue work if there is no async task
- obtain copy op structure directly in uvc_video_decode_data()
- uvc_video_decode_data_work() -> uvc_video_copy_data_work()
v4:
- Provide for_each_uvc_urb()
- Simplify fix for shutdown race to flush queue before freeing URBs
- Rebase to v4.16-rc4 (linux-media/master) adjusting for metadata
conflicts.
2 files changed
