diff mbox

[RFC] s3c-camif: Fail on insufficient number of allocated buffers

Message ID 1360276572-10890-1-git-send-email-sylvester.nawrocki@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sylwester Nawrocki Feb. 7, 2013, 10:36 p.m. UTC 
Ensure the driver gets always at least its minimum required
number of buffers allocated by checking actual number of
allocated buffers in vb2_reqbufs(). And free any partially
allocated buffer queue with signaling an error to user space.

Without this patch applications may wait forever to dequeue
a filled buffer, because the hardware didn't even start after
VIDIOC_STREAMON, VIDIOC_QBUF calls, due to insufficient number
of empty buffers.

Reported-by: Alexander Nestorov <alexandernst@gmail.com>
Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
---
 drivers/media/platform/s3c-camif/camif-capture.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

--
1.7.4.1

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diff mbox

Patch

diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
index a55793c..b8466f3 100644
--- a/drivers/media/platform/s3c-camif/camif-capture.c
+++ b/drivers/media/platform/s3c-camif/camif-capture.c
@@ -934,12 +934,19 @@  static int s3c_camif_reqbufs(struct file *file, void *priv,
 		vp->owner = NULL;

 	ret = vb2_reqbufs(&vp->vb_queue, rb);
-	if (!ret) {
-		vp->reqbufs_count = rb->count;
-		if (vp->owner == NULL && rb->count > 0)
-			vp->owner = priv;
+	if (ret < 0)
+		return ret;
+
+	if (rb->count && rb->count < CAMIF_REQ_BUFS_MIN) {
+		rb->count = 0;
+		vb2_reqbufs(&vp->vb_queue, rb);
+		ret = -ENOMEM;
 	}

+	vp->reqbufs_count = rb->count;
+	if (vp->owner == NULL && rb->count > 0)
+		vp->owner = priv;
+
 	return ret;
 }