Commit 1dc2527c authored by Michal Grzeschik's avatar Michal Grzeschik Committed by Greg Kroah-Hartman
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usb: gadget: uvc: set nbuffers to minimum STREAMING_MIN_BUFFERS in uvc_queue_setup 



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: default avatarMichael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v7-7-e224bb1035f0@pengutronix.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 98ad0329

drivers/usb/gadget/function/uvc.h

+2 −0
Original line number Diff line number Diff line
@@ -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

 */

drivers/usb/gadget/function/uvc_queue.c

+3 −0
Original line number Diff line number Diff line
@@ -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;