From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:50490 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751026AbaB0MHJ (ORCPT ); Thu, 27 Feb 2014 07:07:09 -0500 From: Laurent Pinchart To: Hans Verkuil Cc: linux-media@vger.kernel.org, pawel@osciak.com, s.nawrocki@samsung.com, m.szyprowski@samsung.com, Hans Verkuil Subject: Re: [REVIEWv2 PATCH 10/15] vb2: don't init the list if there are still buffers Date: Thu, 27 Feb 2014 13:08:29 +0100 Message-ID: <1862429.C5S5BLTOjI@avalon> In-Reply-To: <1393332775-44067-11-git-send-email-hverkuil@xs4all.nl> References: <1393332775-44067-1-git-send-email-hverkuil@xs4all.nl> <1393332775-44067-11-git-send-email-hverkuil@xs4all.nl> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, Thank you for the patch. On Tuesday 25 February 2014 13:52:50 Hans Verkuil wrote: > From: Hans Verkuil > > __vb2_queue_free() would init the queued_list at all times, even if > q->num_buffers > 0. This should only happen if num_buffers == 0. > > This situation can happen if a CREATE_BUFFERS call couldn't allocate > enough buffers and had to free those it did manage to allocate before > returning an error. > > While we're at it: __vb2_queue_alloc() returns the number of buffers > allocated, not an error code. So stick the result in allocated_buffers > instead of ret as that's very confusing. > > Signed-off-by: Hans Verkuil Acked-by: Laurent Pinchart > --- > drivers/media/v4l2-core/videobuf2-core.c | 29 +++++++++++++++++------------ > 1 file changed, 17 insertions(+), 12 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c > b/drivers/media/v4l2-core/videobuf2-core.c index 2a7815c..90374c0 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -452,9 +452,10 @@ static int __vb2_queue_free(struct vb2_queue *q, > unsigned int buffers) } > > q->num_buffers -= buffers; > - if (!q->num_buffers) > + if (!q->num_buffers) { > q->memory = 0; > - INIT_LIST_HEAD(&q->queued_list); > + INIT_LIST_HEAD(&q->queued_list); > + } > return 0; > } > > @@ -820,14 +821,12 @@ static int __reqbufs(struct vb2_queue *q, struct > v4l2_requestbuffers *req) } > > /* Finally, allocate buffers and video memory */ > - ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes); > - if (ret == 0) { > + allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, > num_planes); + if (allocated_buffers == 0) { > dprintk(1, "Memory allocation failed\n"); > return -ENOMEM; > } > > - allocated_buffers = ret; > - > /* > * Check if driver can handle the allocated number of buffers. > */ > @@ -851,6 +850,10 @@ static int __reqbufs(struct vb2_queue *q, struct > v4l2_requestbuffers *req) q->num_buffers = allocated_buffers; > > if (ret < 0) { > + /* > + * Note: __vb2_queue_free() will subtract 'allocated_buffers' > + * from q->num_buffers. > + */ > __vb2_queue_free(q, allocated_buffers); > return ret; > } > @@ -924,20 +927,18 @@ static int __create_bufs(struct vb2_queue *q, struct > v4l2_create_buffers *create } > > /* Finally, allocate buffers and video memory */ > - ret = __vb2_queue_alloc(q, create->memory, num_buffers, > + allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers, > num_planes); > - if (ret == 0) { > + if (allocated_buffers == 0) { > dprintk(1, "Memory allocation failed\n"); > return -ENOMEM; > } > > - allocated_buffers = ret; > - > /* > * Check if driver can handle the so far allocated number of buffers. > */ > - if (ret < num_buffers) { > - num_buffers = ret; > + if (allocated_buffers < num_buffers) { > + num_buffers = allocated_buffers; > > /* > * q->num_buffers contains the total number of buffers, that the > @@ -960,6 +961,10 @@ static int __create_bufs(struct vb2_queue *q, struct > v4l2_create_buffers *create q->num_buffers += allocated_buffers; > > if (ret < 0) { > + /* > + * Note: __vb2_queue_free() will subtract 'allocated_buffers' > + * from q->num_buffers. > + */ > __vb2_queue_free(q, allocated_buffers); > return -ENOMEM; > } -- Regards, Laurent Pinchart