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: e81e7f9a0eb9 ("usb: gadget: uvc: add scatter gather support") Cc: stable@vger.kernel.org Signed-off-by: Dan Vacura w36195@motorola.com --- V1 -> V2: - undo error rename - change uvcg_info to uvcg_dbg V2 -> V3: - no changes V3 -> V4: - drop extra cc stable cherry-picks, as a request was made to stable

drivers/usb/gadget/function/uvc_queue.c | 8 +++++--- drivers/usb/gadget/function/uvc_video.c | 18 ++++++++++++++---- 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c index ec500ee499ee..0aa3d7e1f3cc 100644 --- a/drivers/usb/gadget/function/uvc_queue.c +++ b/drivers/usb/gadget/function/uvc_queue.c @@ -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; }

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 323977716f5a..5993e083819c 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -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);