Commit 0a0a2760 authored by Dan Vacura's avatar Dan Vacura Committed by Greg Kroah-Hartman
Browse files

usb: gadget: uvc: fix sg handling in error case 



If there is a transmission error the buffer will be returned too early,
causing a memory fault as subsequent requests for that buffer are still
queued up to be sent. Refactor the error handling to wait for the final
request to come in before reporting back the buffer to userspace for all
transfer types (bulk/isoc/isoc_sg). This ensures userspace knows if the
frame was successfully sent.

Fixes: e81e7f9a ("usb: gadget: uvc: add scatter gather support")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarDan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20221018215044.765044-4-w36195@motorola.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8e8e923a

drivers/usb/gadget/function/uvc_queue.c

+5 −3
Original line number Diff line number Diff line
@@ -304,6 +304,7 @@ int uvcg_queue_enable(struct uvc_video_queue *queue, int enable) 


		queue->sequence = 0;

		queue->buf_used = 0;

		queue->flags &= ~UVC_QUEUE_DROP_INCOMPLETE;

	} else {

		ret = vb2_streamoff(&queue->queue, queue->queue.type);

		if (ret < 0)
@@ -329,10 +330,11 @@ int uvcg_queue_enable(struct uvc_video_queue *queue, int enable) 
void uvcg_complete_buffer(struct uvc_video_queue *queue,

					  struct uvc_buffer *buf)

{

	if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&

	     buf->length != buf->bytesused) {

		buf->state = UVC_BUF_STATE_QUEUED;

	if (queue->flags & UVC_QUEUE_DROP_INCOMPLETE) {

		queue->flags &= ~UVC_QUEUE_DROP_INCOMPLETE;

		buf->state = UVC_BUF_STATE_ERROR;

		vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);

		vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);

		return;

	}

drivers/usb/gadget/function/uvc_video.c

+14 −4
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video, 
		struct uvc_buffer *buf)

{

	void *mem = req->buf;

	struct uvc_request *ureq = req->context;

	int len = video->req_size;

	int ret;
@@ -113,13 +114,14 @@ uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video, 
		video->queue.buf_used = 0;

		buf->state = UVC_BUF_STATE_DONE;

		list_del(&buf->queue);

		uvcg_complete_buffer(&video->queue, buf);

		video->fid ^= UVC_STREAM_FID;

		ureq->last_buf = buf;



		video->payload_size = 0;

	}



	if (video->payload_size == video->max_payload_size ||

	    video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE ||

	    buf->bytesused == video->queue.buf_used)

		video->payload_size = 0;

}
@@ -180,7 +182,8 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video, 
	req->length -= len;

	video->queue.buf_used += req->length - header_len;



	if (buf->bytesused == video->queue.buf_used || !buf->sg) {

	if (buf->bytesused == video->queue.buf_used || !buf->sg ||

			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {

		video->queue.buf_used = 0;

		buf->state = UVC_BUF_STATE_DONE;

		buf->offset = 0;
@@ -195,6 +198,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, 
		struct uvc_buffer *buf)

{

	void *mem = req->buf;

	struct uvc_request *ureq = req->context;

	int len = video->req_size;

	int ret;
@@ -209,12 +213,13 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, 


	req->length = video->req_size - len;



	if (buf->bytesused == video->queue.buf_used) {

	if (buf->bytesused == video->queue.buf_used ||

			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {

		video->queue.buf_used = 0;

		buf->state = UVC_BUF_STATE_DONE;

		list_del(&buf->queue);

		uvcg_complete_buffer(&video->queue, buf);

		video->fid ^= UVC_STREAM_FID;

		ureq->last_buf = buf;

	}

}
@@ -255,6 +260,11 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) 
	case 0:

		break;



	case -EXDEV:

		uvcg_dbg(&video->uvc->func, "VS request missed xfer.\n");

		queue->flags |= UVC_QUEUE_DROP_INCOMPLETE;

		break;



	case -ESHUTDOWN:	/* disconnect from host. */

		uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");

		uvcg_queue_cancel(queue, 1);