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    Subject[PATCH AUTOSEL 5.0 119/262] media: ov7740: fix runtime pm initialization
    Date
    From: Akinobu Mita <akinobu.mita@gmail.com>

    [ Upstream commit 12aceee1f412c3ddc7750155fec06c906f14ab51 ]

    The runtime PM of this device is enabled after v4l2_ctrl_handler_setup(),
    and this makes this device's runtime PM usage count a negative value.

    The ov7740_set_ctrl() tries to do something only if the device's runtime
    PM usage counter is nonzero.

    ov7740_set_ctrl()
    {
    if (!pm_runtime_get_if_in_use(&client->dev))
    return 0;

    <do something>;

    pm_runtime_put(&client->dev);

    return ret;
    }

    However, the ov7740_set_ctrl() is called by v4l2_ctrl_handler_setup()
    while the runtime PM of this device is not yet enabled. In this case,
    the pm_runtime_get_if_in_use() returns -EINVAL (!= 0).

    Therefore we can't bail out of this function and the usage count is
    decreased by pm_runtime_put() without increment.

    This fixes this problem by enabling the runtime PM of this device before
    v4l2_ctrl_handler_setup() so that the ov7740_set_ctrl() is always called
    when the runtime PM is enabled.

    Cc: Wenyou Yang <wenyou.yang@microchip.com>
    Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
    Tested-by: Eugen Hristev <eugen.hristev@microchip.com>
    Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
    Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/media/i2c/ov7740.c | 7 +++++--
    1 file changed, 5 insertions(+), 2 deletions(-)

    diff --git a/drivers/media/i2c/ov7740.c b/drivers/media/i2c/ov7740.c
    index 177688afd9a6..8835b831cdc0 100644
    --- a/drivers/media/i2c/ov7740.c
    +++ b/drivers/media/i2c/ov7740.c
    @@ -1101,6 +1101,9 @@ static int ov7740_probe(struct i2c_client *client,
    if (ret)
    return ret;

    + pm_runtime_set_active(&client->dev);
    + pm_runtime_enable(&client->dev);
    +
    ret = ov7740_detect(ov7740);
    if (ret)
    goto error_detect;
    @@ -1123,8 +1126,6 @@ static int ov7740_probe(struct i2c_client *client,
    if (ret)
    goto error_async_register;

    - pm_runtime_set_active(&client->dev);
    - pm_runtime_enable(&client->dev);
    pm_runtime_idle(&client->dev);

    return 0;
    @@ -1134,6 +1135,8 @@ static int ov7740_probe(struct i2c_client *client,
    error_init_controls:
    ov7740_free_controls(ov7740);
    error_detect:
    + pm_runtime_disable(&client->dev);
    + pm_runtime_set_suspended(&client->dev);
    ov7740_set_power(ov7740, 0);
    media_entity_cleanup(&ov7740->subdev.entity);

    --
    2.19.1
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