Re: [PATCH 4/5] scsi: pm: use runtime resume callback if available

Aaron Lu
2012-07-23T23:30:56Z

Hi,

On Mon, Jul 23, 2012 at 06:36:12PM +0400, Sergei Shtylyov wrote:
> Hello.
>
> On 07/23/2012 10:49 AM, Aaron Lu wrote:
>
> > When runtime resume a scsi device, if the device's driver has
> > implemented runtime resume callback, use that instead of the resume
> > callback.
>
> > sr driver needs this to properly do different things for system resume
> > and runtime resume.
>
> > Signed-off-by: Aaron Lu <aaron.lu@amd.com>
> > ---
> > drivers/scsi/scsi_pm.c | 14 +++++++++-----
> > drivers/scsi/sr.c | 21 +++++++++++++++++++++
> > 2 files changed, 30 insertions(+), 5 deletions(-)
>
> > diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
> > index d4201de..19bba47 100644
> > --- a/drivers/scsi/scsi_pm.c
> > +++ b/drivers/scsi/scsi_pm.c
> > @@ -34,14 +34,18 @@ static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg)
> > return err;
> > }
> >
> > -static int scsi_dev_type_resume(struct device *dev)
> > +static int scsi_dev_type_resume(struct device *dev, bool runtime)
> > {
> > struct device_driver *drv;
> > int err = 0;
> > + int (*resume)(struct device *);
> >
> > drv = dev->driver;
> > - if (drv && drv->resume)
> > - err = drv->resume(dev);
> > + if (runtime && drv && drv->pm && drv->pm->runtime_resume)
> > + resume = drv->pm->runtime_resume;
> > + else
> > + resume = drv ? drv->resume : NULL;
>
> Call thru NULL pointer below will cause kernel oops. Is it your intention?

Oops, I forgot the if check here, thanks for pointing this out.

-Aaron

>
> > + err = resume(dev);
>