Re: [BUG] Device unbound in a resumed state
From: Alan Stern
Date: Fri Mar 11 2016 - 13:46:29 EST
On Fri, 11 Mar 2016, Krzysztof Kozlowski wrote:
> Could be related (the same?) with .
> I have a driver (hwrng/exynos-rng) which in probe does:
> pm_runtime_set_autosuspend_delay(&pdev->dev, EXYNOS_AUTOSUSPEND_DELAY);
> and in remove:
But not pm_runtime_dont_use_autosuspend()?
Why disable runtime PM if you want the runtime-PM methods to put the
device into a low-power state?
> Just before unbinding in __device_release_driver() the device is resumed
> but unfortunately not suspended later. I mean the
> __device_release_driver()->pm_runtime_put_sync() does not trigger
> runtime suspend.
Because autosuspend is still in use at this point.
> This leads to leaving the device in active state (e.g. clocks enabled).
> It does not happen after removal of autosuspend. Also runtime suspend
> happens after very fast unbind-bind.
Overall it sounds like the system is behaving the way it is supposed
But maybe we should make pm_runtime_use_autosuspend() call
pm_runtime_mark_last_busy(), to avoid the unbind - bind - immediate