Vishwanath BS <vishwanath.bs@xxxxxx> writes:
> In current i2c core driver, pm_runtime_set_active call from i2c_device_pm_resume
> is not balanced by pm_runtime_set_suspended call from i2c_device_pm_suspend.
> pm_runtime_set_active called from resume path will increase the child_count of
> the device's parent. However, matching pm_runtime_set_suspended is not called
> in suspend routine because of which child_count of the device's parent
> is not balanced, preventing the parent device to idle.
> Issue has been fixed by adding pm_runtime_set_suspended call inside suspend
> reoutine which will make sure that child_counts are balanced.
> This fix has been tested on OMAP4430.
>
> Signed-off-by: Partha Basak <p-basak2@xxxxxx>
> Signed-off-by: Vishwanath BS <vishwanath.bs@xxxxxx>
>
> Cc: Rafael J. Wysocki <rjw@xxxxxxx>
> Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
> Cc: Ben Dooks <ben-linux@xxxxxxxxx>
Also Cc'ing Mark Brown as original author of runtime PM for i2-core.
Kevin
> ---
> drivers/i2c/i2c-core.c | 12 ++++++++++--
> 1 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 6649176..3146bff
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -196,14 +196,22 @@ static int i2c_legacy_resume(struct device *dev)
> static int i2c_device_pm_suspend(struct device *dev)
> {
> const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
> + int ret;
>
> if (pm_runtime_suspended(dev))
> return 0;
>
> if (pm)
> - return pm->suspend ? pm->suspend(dev) : 0;
> + ret = pm->suspend ? pm->suspend(dev) : 0;
> + else
> + ret = i2c_legacy_suspend(dev, PMSG_SUSPEND);
>
> - return i2c_legacy_suspend(dev, PMSG_SUSPEND);
> + if (!ret) {
> + pm_runtime_disable(dev);
> + pm_runtime_set_suspended(dev);
> + pm_runtime_enable(dev);
> + }
> + return ret;
> }
>
> static int i2c_device_pm_resume(struct device *dev)
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