From 0db8160cf18f92bd666d018bb0a1fed4c8b63769 Mon Sep 17 00:00:00 2001 From: Naushir Patuck Date: Wed, 2 Dec 2020 15:26:09 +0000 Subject: [PATCH 0267/1085] media: bcm2835-unicam: Return early from stop_streaming() if stopped clk_disable_unprepare() is called unconditionally in stop_streaming(). This is incorrect in the cases where start_streaming() fails, and unprepares all clocks as part of the failure cleanup. To avoid this, ensure that clk_disable_unprepare() is only called in stop_streaming() if the clocks are in a prepared state. Signed-off-by: Naushir Patuck --- drivers/media/platform/bcm2835/bcm2835-unicam.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c @@ -428,6 +428,8 @@ struct unicam_device { struct clk *clock; /* vpu clock handle */ struct clk *vpu_clock; + /* clock status for error handling */ + bool clocks_enabled; /* V4l2 device */ struct v4l2_device v4l2_dev; struct media_device mdev; @@ -1726,6 +1728,7 @@ static int unicam_start_streaming(struct goto err_disable_unicam; } + dev->clocks_enabled = true; return 0; err_disable_unicam: @@ -1752,8 +1755,6 @@ static void unicam_stop_streaming(struct node->streaming = false; if (node->pad_id == IMAGE_PAD) { - int ret; - /* * Stop streaming the sensor and disable the peripheral. * We cannot continue streaming embedded data with the @@ -1764,12 +1765,13 @@ static void unicam_stop_streaming(struct unicam_disable(dev); - ret = clk_set_min_rate(dev->vpu_clock, 0); - if (ret) - unicam_err(dev, "failed to reset the min VPU clock\n"); + if (dev->clocks_enabled) { + if (clk_set_min_rate(dev->vpu_clock, 0)) + unicam_err(dev, "failed to reset the min VPU clock\n"); - clk_disable_unprepare(dev->vpu_clock); - clk_disable_unprepare(dev->clock); + clk_disable_unprepare(dev->vpu_clock); + clk_disable_unprepare(dev->clock); + } unicam_runtime_put(dev); } else if (node->pad_id == METADATA_PAD) {