On Thu, Apr 10, 2014 at 3:59 PM, Ulf Hansson <[email protected]> wrote:

> For !CONFIG_PM_RUNTIME, the device were never put back into active
> state while resuming.
>
> For CONFIG_PM_RUNTIME, we blindly trusted the device to be inactive
> while we were about to handle it at suspend late, which is just too
> optimistic.
>
> Even if the driver uses pm_runtime_put_sync() after each tranfer to
> return it's runtime PM resources, there are no guarantees this will
> actually mean the device will inactivated. The reason is that the PM
> core will prevent runtime suspend during system suspend, and thus when
> a transfer occurs during the early phases of system suspend the device
> will be kept active after the transfer.
>
> To handle both issues above, use pm_runtime_force_suspend|resume() from
> the system suspend|resume callbacks.
>
> Cc: Alessandro Rubini <[email protected]>
> Cc: Linus Walleij <[email protected]>
> Cc: Wolfram Sang <[email protected]>
> Signed-off-by: Ulf Hansson <[email protected]>

Acked-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to