On Thursday, September 27, 2012, Aaron Lu wrote: > On 09/27/2012 10:42 PM, Alan Stern wrote: > > On Thu, 27 Sep 2012, Aaron Lu wrote: > > > >>> Moreover, I'd like to migrate SCSI drivers to the PM handling based on struct > >>> dev_pm_ops eventually and your change is kind of going in the opposite > >>> direction. I don't know how much effort the migration is going to take, > >>> though, so perhaps we can just make this change first. > >> > >> Does the following change look OK? > >> > >> diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c > >> index dc0ad85..1fb7ccc 100644 > >> --- a/drivers/scsi/scsi_pm.c > >> +++ b/drivers/scsi/scsi_pm.c > >> @@ -143,7 +143,15 @@ static int scsi_runtime_suspend(struct device *dev) > >> > >> dev_dbg(dev, "scsi_runtime_suspend\n"); > >> if (scsi_is_sdev_device(dev)) { > >> - err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND); > >> + err = scsi_device_quiesce(to_scsi_device(dev)); > >> + if (err) > >> + goto out; > >> + > >> + err = pm_generic_runtime_suspend(dev); > >> + if (!err) > >> + goto out; > >> + > >> + scsi_device_resume(to_scsi_device(dev)); > >> if (err == -EAGAIN) > >> pm_schedule_suspend(dev, jiffies_to_msecs( > >> round_jiffies_up_relative(HZ/10))); > > > > Maybe in the end it will be better, but for now this looks like > > unnecessary code duplication. Basically you are copying > > scsi_dev_type_suspend() into scsi_runtime_suspend(), except that you > > omitted the debugging statement. > > And I've used pm_generic_runtime_suspend :-) > That would allow me to write runtime callbacks of dev_pm_ops for > indivisual scsi drivers, like sr. Well, actually, I meant something different. The above patch would make it possible for drivers to provide runtime PM callbacks through dev->driver.pm, but drv->suspend and drv->resume would still be used for system suspend/resume (and hibernation). The transition to struct dev_pm_ops I meant, however, would be to start using callbacks from dev->driver.pm for _all_ device PM operations by default and fall back to drv->suspend and drv->resume for the drivers whose dev->driver.pm is NULL (along the lines of what PCI does). The next step would be to convert all drivers to use dev->driver.pm only. So I wouldn't like any drivers to use dev->driver.pm callbacks for some operations and drv->suspend and drv->resume for the remaining ones at the same time. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html