On 09/22/2012 05:02 AM, Rafael J. Wysocki wrote:
> On Friday, September 21, 2012, Aaron Lu wrote:
>> On Fri, Sep 21, 2012 at 12:07:23AM +0200, Rafael J. Wysocki wrote:
>>> On Wednesday, September 12, 2012, Aaron Lu wrote:
>>>> static struct scsi_driver sr_template = {
>>>> .owner = THIS_MODULE,
>>>> @@ -87,6 +89,8 @@ static struct scsi_driver sr_template = {
>>>> .name = "sr",
>>>> .probe = sr_probe,
>>>> .remove = sr_remove,
>>>> + .suspend = sr_suspend,
>>>> + .resume = sr_resume,
>>>> },
>>>> .done = sr_done,
>>>> };
>>>> @@ -172,6 +176,52 @@ static void scsi_cd_put(struct scsi_cd *cd)
>>>> mutex_unlock(&sr_ref_mutex);
>>>> }
>>>
>>> Besides, I need some help to understand how this is supposed to work.
>>>
>>> Do I think correctly that sr_suspend(), for example, will be run by the
>>> SCSI bus type layer in case of a CD device runtime suspend? However,
>>
>> Yes.
>>
>>> won't this routine be used during system suspend as well and won't it cause
>>> problems to happen if so?
>>
>> On system suspend, nothing needs to be done.
>> I'll add the following code in next version.
>>
>> if (!PMSG_IS_AUTO(msg))
>> return 0;
>
> Please don't. The pm_message_t thing is obsolete and shoulnd't really be
> used by device drivers. I know that ATA relies on it internally, but that's
> just something that needs to be changed at one point.
>
> 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)));
@@ -151,6 +159,7 @@ static int scsi_runtime_suspend(struct device *dev)
/* Insert hooks here for targets, hosts, and transport classes */
+out:
return err;
}
@@ -159,11 +168,17 @@ static int scsi_runtime_resume(struct device *dev)
int err = 0;
dev_dbg(dev, "scsi_runtime_resume\n");
- if (scsi_is_sdev_device(dev))
+ if (scsi_is_sdev_device(dev)) {
+ err = pm_generic_runtime_resume(dev);
+ if (err)
+ goto out;
+
err = scsi_dev_type_resume(dev);
+ }
/* Insert hooks here for targets, hosts, and transport classes */
+out:
return err;
}
And I'll define runtime callbacks for sr and sd.
Thanks,
Aaron
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