Re: [PATCH] PM: runtime: return at once for active device in rpm_resume

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, June 14, 2011, tom.leiming@gmail.com wrote:
> From: Ming Lei <tom.leiming@gmail.com>
> 
> This patch moves ahead check for active rpm state of device,
> so that rpm_resume can return immediately for device with
> active rpm state.
> 
> Considered rpm_resume is run in atomic context and is often in
> hot path(such as in usbnet, called before transmitting every
> network frame), this patch should make sense.

It ignores the fact that rpm_resume() cancels pending runtime PM requests
in addition to resuming suspended devices.

Thanks,
Rafael


> Signed-off-by: Ming Lei <tom.leiming@gmail.com>
> ---
>  drivers/base/power/runtime.c |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 0d4587b..dcc3008 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -455,6 +455,11 @@ static int rpm_resume(struct device *dev, int rpmflags)
>  	dev_dbg(dev, "%s flags 0x%x\n", __func__, rpmflags);
>  
>   repeat:
> +	if (dev->power.runtime_status == RPM_ACTIVE) {
> +		retval = 1;
> +		goto out;
> +	}
> +
>  	if (dev->power.runtime_error)
>  		retval = -EINVAL;
>  	else if (dev->power.disable_depth > 0)
> @@ -472,11 +477,6 @@ static int rpm_resume(struct device *dev, int rpmflags)
>  	if (!dev->power.timer_autosuspends)
>  		pm_runtime_deactivate_timer(dev);
>  
> -	if (dev->power.runtime_status == RPM_ACTIVE) {
> -		retval = 1;
> -		goto out;
> -	}
> -
>  	if (dev->power.runtime_status == RPM_RESUMING
>  	    || dev->power.runtime_status == RPM_SUSPENDING) {
>  		DEFINE_WAIT(wait);
>