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media: i2c: ccs-core: fix pm_runtime_get_sync() usage count

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The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.

There is a bug at ccs_pm_get_init(): when this function returns
an error, the stream is not started, and RPM usage_count
should not be incremented. However, if the calls to
v4l2_ctrl_handler_setup() return errors, it will be kept
incremented.

At ccs_suspend() the best is to replace it by the new
pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a8 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
in order to properly decrement the usage counter automatically,
in the case of errors.

Fixes: 96e3a6b92f ("media: smiapp: Avoid maintaining power state information")
Cc: stable@vger.kernel.org
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Mauro Carvalho Chehab 2021-04-23 17:19:11 +02:00
parent 6005a8e955
commit da3a1858c3
1 changed files with 22 additions and 10 deletions
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32
drivers/media/i2c/ccs/ccs-core.c
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@ -1880,21 +1880,33 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor)
struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
int rval;
/*
* It can't use pm_runtime_resume_and_get() here, as the driver
* relies at the returned value to detect if the device was already
* active or not.
*/
rval = pm_runtime_get_sync(&client->dev);
if (rval < 0) {
pm_runtime_put_noidle(&client->dev);
if (rval < 0)
goto error;
return rval;
} else if (!rval) {
rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->
ctrl_handler);
if (rval)
return rval;
/* Device was already active, so don't set controls */
if (rval == 1)
return 0;
return v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
}
/* Restore V4L2 controls to the previously suspended device */
rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->ctrl_handler);
if (rval)
goto error;
rval = v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
if (rval)
goto error;
/* Keep PM runtime usage_count incremented on success */
return 0;
error:
pm_runtime_put(&client->dev);
return rval;
}
static int ccs_set_stream(struct v4l2_subdev *subdev, int enable)