Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755917AbaJGXhq (ORCPT ); Tue, 7 Oct 2014 19:37:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39518 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755579AbaJGXTy (ORCPT ); Tue, 7 Oct 2014 19:19:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hans Verkuil , Laurent Pinchart , Mauro Carvalho Chehab Subject: [PATCH 3.16 25/26] media: vb2: fix VBI/poll regression Date: Tue, 7 Oct 2014 16:19:41 -0700 Message-Id: <20141007231849.225482465@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141007231848.487609292@linuxfoundation.org> References: <20141007231848.487609292@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hans Verkuil commit 58d75f4b1ce26324b4d809b18f94819843a98731 upstream. The recent conversion of saa7134 to vb2 unconvered a poll() bug that broke the teletext applications alevt and mtt. These applications expect that calling poll() without having called VIDIOC_STREAMON will cause poll() to return POLLERR. That did not happen in vb2. This patch fixes that behavior. It also fixes what should happen when poll() is called when STREAMON is called but no buffers have been queued. In that case poll() will also return POLLERR, but only for capture queues since output queues will always return POLLOUT anyway in that situation. This brings the vb2 behavior in line with the old videobuf behavior. Signed-off-by: Hans Verkuil Acked-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/v4l2-core/videobuf2-core.c | 15 +++++++++++++-- include/media/videobuf2-core.h | 4 ++++ 2 files changed, 17 insertions(+), 2 deletions(-) --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -967,6 +967,7 @@ static int __reqbufs(struct vb2_queue *q * to the userspace. */ req->count = allocated_buffers; + q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type); return 0; } @@ -1014,6 +1015,7 @@ static int __create_bufs(struct vb2_queu memset(q->plane_sizes, 0, sizeof(q->plane_sizes)); memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx)); q->memory = create->memory; + q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type); } num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers); @@ -1812,6 +1814,7 @@ static int vb2_internal_qbuf(struct vb2_ */ list_add_tail(&vb->queued_entry, &q->queued_list); q->queued_count++; + q->waiting_for_buffers = false; vb->state = VB2_BUF_STATE_QUEUED; if (V4L2_TYPE_IS_OUTPUT(q->type)) { /* @@ -2244,6 +2247,7 @@ static int vb2_internal_streamoff(struct * their normal dequeued state. */ __vb2_queue_cancel(q); + q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type); dprintk(3, "successful\n"); return 0; @@ -2562,9 +2566,16 @@ unsigned int vb2_poll(struct vb2_queue * } /* - * There is nothing to wait for if no buffers have already been queued. + * There is nothing to wait for if the queue isn't streaming. */ - if (list_empty(&q->queued_list)) + if (!vb2_is_streaming(q)) + return res | POLLERR; + /* + * For compatibility with vb1: if QBUF hasn't been called yet, then + * return POLLERR as well. This only affects capture queues, output + * queues will always initialize waiting_for_buffers to false. + */ + if (q->waiting_for_buffers) return res | POLLERR; if (list_empty(&q->done_list)) --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -375,6 +375,9 @@ struct v4l2_fh; * @streaming: current streaming state * @start_streaming_called: start_streaming() was called successfully and we * started streaming. + * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for + * buffers. Only set for capture queues if qbuf has not yet been + * called since poll() needs to return POLLERR in that situation. * @fileio: file io emulator internal data, used only if emulator is active * @threadio: thread io internal data, used only if thread is active */ @@ -411,6 +414,7 @@ struct vb2_queue { unsigned int streaming:1; unsigned int start_streaming_called:1; + unsigned int waiting_for_buffers:1; struct vb2_fileio_data *fileio; struct vb2_threadio_data *threadio; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/