git.openwrt.org Git - openwrt/openwrt.git/blob

   1 From 1e888ff376c880b2803aecea3f69d28dc2ae4349 Mon Sep 17 00:00:00 2001
   2 From: Naushir Patuck <naush@raspberrypi.com>
   3 Date: Wed, 2 Dec 2020 15:26:09 +0000
   4 Subject: [PATCH] media: bcm2835-unicam: Return early from
   5  stop_streaming() if stopped
   6
   7 clk_disable_unprepare() is called unconditionally in stop_streaming().
   8 This is incorrect in the cases where start_streaming() fails, and
   9 unprepares all clocks as part of the failure cleanup. To avoid this,
  10 ensure that clk_disable_unprepare() is only called in stop_streaming()
  11 if the clocks are in a prepared state.
  12
  13 Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
  14 ---
  15  drivers/media/platform/bcm2835/bcm2835-unicam.c | 16 +++++++++-------
  16  1 file changed, 9 insertions(+), 7 deletions(-)
  17
  18 --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
  19 +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
  20 @@ -426,6 +426,8 @@ struct unicam_device {
  21         struct clk *clock;
  22         /* vpu clock handle */
  23         struct clk *vpu_clock;
  24 +       /* clock status for error handling */
  25 +       bool clocks_enabled;
  26         /* V4l2 device */
  27         struct v4l2_device v4l2_dev;
  28         struct media_device mdev;
  29 @@ -1724,6 +1726,7 @@ static int unicam_start_streaming(struct
  30                 goto err_disable_unicam;
  31         }
  32
  33 +       dev->clocks_enabled = true;
  34         return 0;
  35
  36  err_disable_unicam:
  37 @@ -1750,8 +1753,6 @@ static void unicam_stop_streaming(struct
  38         node->streaming = false;
  39
  40         if (node->pad_id == IMAGE_PAD) {
  41 -               int ret;
  42 -
  43                 /*
  44                  * Stop streaming the sensor and disable the peripheral.
  45                  * We cannot continue streaming embedded data with the
  46 @@ -1762,12 +1763,13 @@ static void unicam_stop_streaming(struct
  47
  48                 unicam_disable(dev);
  49
  50 -               ret = clk_set_min_rate(dev->vpu_clock, 0);
  51 -               if (ret)
  52 -                       unicam_err(dev, "failed to reset the min VPU clock\n");
  53 +               if (dev->clocks_enabled) {
  54 +                       if (clk_set_min_rate(dev->vpu_clock, 0))
  55 +                               unicam_err(dev, "failed to reset the min VPU clock\n");
  56
  57 -               clk_disable_unprepare(dev->vpu_clock);
  58 -               clk_disable_unprepare(dev->clock);
  59 +                       clk_disable_unprepare(dev->vpu_clock);
  60 +                       clk_disable_unprepare(dev->clock);
  61 +               }
  62                 unicam_runtime_put(dev);
  63
  64         } else if (node->pad_id == METADATA_PAD) {