[PATCH 1/1] vb2: Enforce VB2_MAX_FRAME in vb2_core_reqbufs better

[Sakari Ailus]

The check for the number of buffers requested against the maximum,
VB2_MAX_FRAME, was performed before checking queue's minimum number of
buffers. Reverse the order, thus ensuring that under no circumstances
num_buffers exceeds VB2_MAX_FRAME here.

Also add a warning of the condition.

Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c 
b/drivers/media/v4l2-core/videobuf2-core.c
index a8589d96ef72..7cade8189bf2 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -696,8 +696,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory 
memory,
        /*
         * Make sure the requested values and current defaults are sane.
         */
-       num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
-       num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
+       WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
+       num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
+       num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
        memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
        q->memory = memory;
 
-- 
2.11.0