Re: [PATCH 4.13 10/36] PM / QoS: Fix default runtime_pm device resume latency

[Rafael J. Wysocki]

On 11/6/2017 10:12 AM, Greg Kroah-Hartman wrote:
> 4.13-stable review patch.  If anyone has any objections, please let me know.

Please drop this from the -stable queue, it has been reverted from the 
mainline.

Thanks,

Rafael


> ------------------
>
> From: Tero Kristo <t-kristo@xxxxxx>
>
> commit 2a9a86d5c81389cd9afe6a4fea42c585733cd705 upstream.
>
> The recent change to the PM QoS framework to introduce a proper
> no constraint value overlooked to handle the devices which don't
> implement PM QoS OPS.  Runtime PM is one of the more severely
> impacted subsystems, failing every attempt to runtime suspend
> a device.  This leads into some nasty second level issues like
> probe failures and increased power consumption among other
> things.
>
> Fix this by adding a proper return value for devices that don't
> implement PM QoS.
>
> Fixes: 0cc2b4e5a020 (PM / QoS: Fix device resume latency PM QoS)
> Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
> ---
>   include/linux/pm_qos.h |    3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- a/include/linux/pm_qos.h
> +++ b/include/linux/pm_qos.h
> @@ -175,7 +175,8 @@ static inline s32 dev_pm_qos_requested_f
>   static inline s32 dev_pm_qos_raw_read_value(struct device *dev)
>   {
>   	return IS_ERR_OR_NULL(dev->power.qos) ?
> -		0 : pm_qos_read_value(&dev->power.qos->resume_latency);
> +		PM_QOS_RESUME_LATENCY_NO_CONSTRAINT :
> +		pm_qos_read_value(&dev->power.qos->resume_latency);
>   }
>   #else
>   static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,