On 11 February 2016 at 00:02, Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> Drivers using pm_runtime_use_autosuspend() may not get disabled after
> -EPROBE_DEFER. On the following device driver probe, hardware state
> is different from the PM runtime state causing omap_device to produce
> the following error:
>
> omap_device_enable() called from invalid state 1
>
> And with omap_device and omap hardware being picky for PM, this will
> block any deeper idle states in hardware.
>
> Let's add a proper error message so driver writers can easily fix
> their drivers for PM.
>
> In general, the solution is to fix the drivers to follow the PM
> runtime documentation:
>
> 1. For sections of code that needs the device disabled, use
> pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
> been set.
>
> 2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
> pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
> set.
>
> Let's not return with 0 from _od_runtime_resume() as that will
> eventually lead into new drivers with broken PM runtime that will
> block deeper idle states on omaps.
>
> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
> Cc: Nishanth Menon <nm@xxxxxx>
> Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx>
> Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> Cc: Tero Kristo <t-kristo@xxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Kind regards
Uffe
> ---
> arch/arm/mach-omap2/omap_device.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
> index 0437537..ebd8369 100644
> --- a/arch/arm/mach-omap2/omap_device.c
> +++ b/arch/arm/mach-omap2/omap_device.c
> @@ -602,8 +602,10 @@ static int _od_runtime_resume(struct device *dev)
> int ret;
>
> ret = omap_device_enable(pdev);
> - if (ret)
> + if (ret) {
> + dev_err(dev, "use pm_runtime_put_sync_suspend() in driver?\n");
> return ret;
> + }
>
> return pm_generic_runtime_resume(dev);
> }
> --
> 2.7.0
>
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