[PATCH v2 3/3] usb: gadget: uvc: decrease the interrupt load to a quarter
From: Michael Grzeschik <hidden>
Date: 2021-05-30 22:30:56
Subsystem:
the rest, usb subsystem, usb webcam gadget · Maintainers:
Linus Torvalds, Greg Kroah-Hartman
With usb3 we handle much more requests. It only enables the interrupt on every quarter of the allocated requests. This patch decreases the interrupt load. Signed-off-by: Michael Grzeschik <redacted> --- drivers/usb/gadget/function/uvc.h | 2 ++ drivers/usb/gadget/function/uvc_video.c | 12 ++++++++++++ 2 files changed, 14 insertions(+)
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index c1f06d9df5820..5a76e9351b530 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; + 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 240d361a45a44..66754687ce217 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c@@ -357,6 +357,16 @@ static void uvcg_video_pump(struct work_struct *work) video->encode(req, video, buf); + 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);
@@ -365,6 +375,7 @@ 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);
@@ -437,6 +448,7 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) video->width = 320; video->height = 240; video->imagesize = 320 * 240 * 2; + video->req_int_count = 0; /* Initialize the video buffers queue. */ uvcg_queue_init(uvc->v4l2_dev.dev, &video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT,
--
2.29.2