We set the minimum amount of v4l2 buffers that is possibly be pending
to UVCG_STREAMING_MIN_BUFFERS which is two. This way the driver will
always have at least one frame pending to be encoded while the other
is being enqueued in the hardware.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
v5 -> v7: -
v4 -> v5:
- using STREAMING_MIN_BUFFERS set the min nbuffers
- renamed the patch since the function changed
- removed the g_ctrl function
- reordered this patch in the series
v1 -> v4: -
---
drivers/usb/gadget/function/uvc.h | 2 ++
drivers/usb/gadget/function/uvc_queue.c | 3 +++
2 files changed, 5 insertions(+)
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index bedb4ef42864f..6f44dd7323150 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -74,6 +74,8 @@ extern unsigned int uvc_gadget_trace_param;
#define UVCG_REQ_MAX_INT_COUNT 16
#define UVCG_REQ_MAX_ZERO_COUNT (2 * UVCG_REQ_MAX_INT_COUNT)
+#define UVCG_STREAMING_MIN_BUFFERS 2
+
/* ------------------------------------------------------------------------
* Structures
*/
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
index 6757a4e25a743..5eaeae3e2441c 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -21,6 +21,7 @@
#include <media/videobuf2-vmalloc.h>
#include "uvc.h"
+#include "uvc_video.h"
/* ------------------------------------------------------------------------
* Video buffers queue management.
@@ -47,6 +48,8 @@ static int uvc_queue_setup(struct vb2_queue *vq,
if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
*nbuffers = UVC_MAX_VIDEO_BUFFERS;
+ if (*nbuffers < UVCG_STREAMING_MIN_BUFFERS)
+ *nbuffers = UVCG_STREAMING_MIN_BUFFERS;
*nplanes = 1;
--
2.39.5