target/linux/bcm27xx/patches-5.10/950-0254-media-bcm2835-unicam-change-minimum-number-of-vb2_qu.patch

   1 From f858ff156427e99d5abeebc80c666caab33b3637 Mon Sep 17 00:00:00 2001
   2 From: David Plowman <david.plowman@raspberrypi.com>
   3 Date: Thu, 28 May 2020 11:09:48 +0100
   4 Subject: [PATCH] media: bcm2835-unicam: change minimum number of
   5  vb2_queue buffers to 1
   6
   7 Since the unicam driver was modified to write to a dummy buffer when no
   8 user-supplied buffer is available, it can now write to and return a
   9 buffer even when there's only a single one. Enable this by changing the
  10 min_buffers_needed in the vb2_queue; it will be useful for enabling
  11 still captures without allocating more memory than absolutely necessary.
  12
  13 Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
  14 ---
  15  drivers/media/platform/bcm2835/bcm2835-unicam.c | 2 +-
  16  1 file changed, 1 insertion(+), 1 deletion(-)
  17
  18 --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
  19 +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
  20 @@ -2404,7 +2404,7 @@ static int register_node(struct unicam_d
  21         q->buf_struct_size = sizeof(struct unicam_buffer);
  22         q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
  23         q->lock = &node->lock;
  24 -       q->min_buffers_needed = 2;
  25 +       q->min_buffers_needed = 1;
  26         q->dev = &unicam->pdev->dev;
  27
  28         ret = vb2_queue_init(q);