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Commit 635fabdd authored by Akinobu Mita's avatar Akinobu Mita Committed by Greg Kroah-Hartman
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media: ov7740: fix runtime pm initialization 



[ 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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Tested-by: default avatarEugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 1d836ce7

drivers/media/i2c/ov7740.c

+5 −2
Original line number Diff line number Diff line
@@ -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);