diff options
| author | Michael Grzeschik <m.grzeschik@pengutronix.de> | 2021-06-28 18:53:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-27 16:59:19 +0300 |
| commit | fc78941d8169cba40e420eb24a88789b0406c738 (patch) | |
| tree | f2778995fc0993797696a4d44962404dae39b89b /drivers/usb/gadget | |
| parent | e81e7f9a0eb9536d5976acf5d95290338032a198 (diff) | |
| download | linux-fc78941d8169cba40e420eb24a88789b0406c738.tar.xz | |
usb: gadget: uvc: decrease the interrupt load to a quarter
With usb3 we handle many more requests. Decrease the interrupt load by
only enabling the interrupt every quarter of the allocated requests.
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
--
v1 -> v2: - edited patch description
- removed extra parantheses
- added a comment for the logic
- using unsigned int instead of int
- reinitializing req_int_count in uvcg_video_enable
v2 -> v3: -
Link: https://lore.kernel.org/r/20210628155311.16762-6-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/function/uvc.h | 2 | ||||
| -rw-r--r-- | drivers/usb/gadget/function/uvc_video.c | 16 |
2 files changed, 18 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 36b78f8b3cd4..255a61bd6a6a 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -101,6 +101,8 @@ struct uvc_video { struct list_head req_free; spinlock_t req_lock; + unsigned int req_int_count; + void (*encode) (struct usb_request *req, struct uvc_video *video, struct uvc_buffer *buf); diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 2cefb8bd4f15..b4a763e5f70e 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -360,6 +360,19 @@ static void uvcg_video_pump(struct work_struct *work) video->encode(req, video, buf); + /* With usb3 we have more requests. This will decrease the + * interrupt load to a quarter but also catches the corner + * cases, which needs to be handled */ + if (list_empty(&video->req_free) || + buf->state == UVC_BUF_STATE_DONE || + !(video->req_int_count % + DIV_ROUND_UP(video->uvc_num_requests, 4))) { + video->req_int_count = 0; + req->no_interrupt = 0; + } else { + req->no_interrupt = 1; + } + /* Queue the USB request */ ret = uvcg_video_ep_queue(video, req); spin_unlock_irqrestore(&queue->irqlock, flags); @@ -368,6 +381,7 @@ static void uvcg_video_pump(struct work_struct *work) uvcg_queue_cancel(queue, 0); break; } + video->req_int_count++; } spin_lock_irqsave(&video->req_lock, flags); @@ -416,6 +430,8 @@ int uvcg_video_enable(struct uvc_video *video, int enable) video->encode = video->queue.use_sg ? uvc_video_encode_isoc_sg : uvc_video_encode_isoc; + video->req_int_count = 0; + schedule_work(&video->pump); return ret; |