| Message ID | 1343026180-22236-3-git-send-email-aaron.lu@amd.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Mon, 23 Jul 2012, Aaron Lu wrote: > The ODD can either be runtime resumed by the user or by a software > request. And for the latter part, we only support runtime resume the ODD > when the eject request is received. We did this in sr's block ioctl > function, this looks ugly. > > Change this by runtime resuming the ODD in its open function and runtime > suspending it in its release function. > > The downside of this approach is that in old distros with old udisk > daemon, the ODD will be polled by udisk daemon so open/close will > constantly be called, which will cause the ODD frequently resume from > suspend state, breaking the effect of power saving. User with such a > distro is advised to issue a udisk command to inhibit polling of the > disk like this: > $ udisks --inhibit-polling /dev/sr0 > And since newer kernel has in kernel polling, there is no problem > regarding ODD's event report. > > Signed-off-by: Aaron Lu <aaron.lu@amd.com> > --- > drivers/scsi/sr.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c > index 5f4d19a..f7a7635 100644 > --- a/drivers/scsi/sr.c > +++ b/drivers/scsi/sr.c > @@ -152,8 +152,15 @@ static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk) > kref_get(&cd->kref); > if (scsi_device_get(cd->device)) > goto out_put; > + if (pm_runtime_get_sync(&cd->device->sdev_gendev) < 0) { > + pm_runtime_put_noidle(&cd->device->sdev_gendev); > + goto out_pm; > + } You should use scsi_autopm_get_device instead of bypassing the SCSI layer. Similarly for the _put call. I know the existing calls do this already. They shouldn't. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 5f4d19a..f7a7635 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -152,8 +152,15 @@ static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk) kref_get(&cd->kref); if (scsi_device_get(cd->device)) goto out_put; + if (pm_runtime_get_sync(&cd->device->sdev_gendev) < 0) { + pm_runtime_put_noidle(&cd->device->sdev_gendev); + goto out_pm; + } goto out; + out_pm: + scsi_device_put(cd->device); + out_put: kref_put(&cd->kref, sr_kref_release); cd = NULL; @@ -169,6 +176,8 @@ static void scsi_cd_put(struct scsi_cd *cd) mutex_lock(&sr_ref_mutex); kref_put(&cd->kref, sr_kref_release); scsi_device_put(sdev); + pm_runtime_mark_last_busy(&cd->device->sdev_gendev); + pm_runtime_put_autosuspend(&cd->device->sdev_gendev); mutex_unlock(&sr_ref_mutex); } @@ -654,13 +663,6 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, void __user *argp = (void __user *)arg; int ret; - /* Make sure the ODD is not suspended */ - ret = pm_runtime_get_sync(&sdev->sdev_gendev); - if (ret < 0) { - pm_runtime_put_noidle(&sdev->sdev_gendev); - return -EACCES; - } - mutex_lock(&sr_mutex); /* @@ -692,8 +694,6 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, out: mutex_unlock(&sr_mutex); - pm_runtime_mark_last_busy(&cd->device->sdev_gendev); - pm_runtime_put_autosuspend(&cd->device->sdev_gendev); return ret; }
The ODD can either be runtime resumed by the user or by a software request. And for the latter part, we only support runtime resume the ODD when the eject request is received. We did this in sr's block ioctl function, this looks ugly. Change this by runtime resuming the ODD in its open function and runtime suspending it in its release function. The downside of this approach is that in old distros with old udisk daemon, the ODD will be polled by udisk daemon so open/close will constantly be called, which will cause the ODD frequently resume from suspend state, breaking the effect of power saving. User with such a distro is advised to issue a udisk command to inhibit polling of the disk like this: $ udisks --inhibit-polling /dev/sr0 And since newer kernel has in kernel polling, there is no problem regarding ODD's event report. Signed-off-by: Aaron Lu <aaron.lu@amd.com> --- drivers/scsi/sr.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)