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@xxxxxxxxx>
Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@xxxxxxxxx>
---
drivers/media/platform/s3c-camif/camif-capture.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)
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;
}
--
1.7.4.1
--
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