diff mbox

scsi: sr: use block layer runtime PM

Message ID 52281C16.5040108@intel.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Aaron Lu Sept. 5, 2013, 5:52 a.m. UTC
Migrate SCSI Optical Disk Drive(ODD) driver sr to make use of block
layer runtime PM. Accordingly, the SCSI bus layer runtime PM callback is
simplified as all SCSI devices that implement runtime PM are now request
based.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
---
Note that due to ODD will be polled every 2 seconds, for suspend to
actually happen, the autosuspend_delay can not be set to more than 2
seconds.

Also, make sure to use the util-linux utility of version 2.23.2 or later,
as there is a bug fix for eject command to correctly update the ODD's
locked state. If the fix is not applied, after the ODD is ejected with the
eject command, it will not be able to enter runtime suspend state any
more due to SCSI EH code will submit a lock door command for the ODD
right after its parent ATA port is runtime suspended.
https://git.kernel.org/cgit/utils/util-linux/util-linux.git/commit/?id=12272030e563201e0b06732d8a87d8cea7157a04

 drivers/scsi/scsi_pm.c | 58 ++++++++++++--------------------------------------
 drivers/scsi/sr.c      | 37 +++++++++++---------------------
 2 files changed, 27 insertions(+), 68 deletions(-)

Comments

Alan Stern Sept. 5, 2013, 2:25 p.m. UTC | #1
On Thu, 5 Sep 2013, Aaron Lu wrote:

> Migrate SCSI Optical Disk Drive(ODD) driver sr to make use of block
> layer runtime PM. Accordingly, the SCSI bus layer runtime PM callback is
> simplified as all SCSI devices that implement runtime PM are now request
> based.
> 
> Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> ---
> Note that due to ODD will be polled every 2 seconds, for suspend to
> actually happen, the autosuspend_delay can not be set to more than 2
> seconds.

Or the polling delay must be increased.

> Also, make sure to use the util-linux utility of version 2.23.2 or later,
> as there is a bug fix for eject command to correctly update the ODD's
> locked state. If the fix is not applied, after the ODD is ejected with the
> eject command, it will not be able to enter runtime suspend state any
> more due to SCSI EH code will submit a lock door command for the ODD
> right after its parent ATA port is runtime suspended.
> https://git.kernel.org/cgit/utils/util-linux/util-linux.git/commit/?id=12272030e563201e0b06732d8a87d8cea7157a04

I think this patch will cause a compile warning if you have
CONFIG_PM_RUNTIME set and CONFIG_PM_SLEEP disabled.  The
scsi_dev_type_suspend and scsi_dev_type_resume routines will be defined
but not used.

Otherwise it seems okay.

Alan Stern

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Aaron Lu Sept. 6, 2013, 1:36 a.m. UTC | #2
On 09/05/2013 10:25 PM, Alan Stern wrote:
> On Thu, 5 Sep 2013, Aaron Lu wrote:
> 
>> Migrate SCSI Optical Disk Drive(ODD) driver sr to make use of block
>> layer runtime PM. Accordingly, the SCSI bus layer runtime PM callback is
>> simplified as all SCSI devices that implement runtime PM are now request
>> based.
>>
>> Signed-off-by: Aaron Lu <aaron.lu@intel.com>
>> ---
>> Note that due to ODD will be polled every 2 seconds, for suspend to
>> actually happen, the autosuspend_delay can not be set to more than 2
>> seconds.
> 
> Or the polling delay must be increased.
> 
>> Also, make sure to use the util-linux utility of version 2.23.2 or later,
>> as there is a bug fix for eject command to correctly update the ODD's
>> locked state. If the fix is not applied, after the ODD is ejected with the
>> eject command, it will not be able to enter runtime suspend state any
>> more due to SCSI EH code will submit a lock door command for the ODD
>> right after its parent ATA port is runtime suspended.
>> https://git.kernel.org/cgit/utils/util-linux/util-linux.git/commit/?id=12272030e563201e0b06732d8a87d8cea7157a04
> 
> I think this patch will cause a compile warning if you have
> CONFIG_PM_RUNTIME set and CONFIG_PM_SLEEP disabled.  The
> scsi_dev_type_suspend and scsi_dev_type_resume routines will be defined
> but not used.

Oh, right, thanks for the remind. I'll move CONFIG_PM_SLEEP up to cover
scsi_dev_type_suspend/resume in v2.

> 
> Otherwise it seems okay.
>

Thanks,
Aaron
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diff mbox

Patch

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index 4c5aabe..752edf0 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -144,38 +144,22 @@  static int scsi_bus_restore(struct device *dev)
 
 #ifdef CONFIG_PM_RUNTIME
 
-static int sdev_blk_runtime_suspend(struct scsi_device *sdev,
-					int (*cb)(struct device *))
+static int sdev_runtime_suspend(struct device *dev)
 {
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+	struct scsi_device *sdev = to_scsi_device(dev);
 	int err;
 
 	err = blk_pre_runtime_suspend(sdev->request_queue);
 	if (err)
 		return err;
-	if (cb)
-		err = cb(&sdev->sdev_gendev);
+	if (pm && pm->runtime_suspend)
+		err = pm->runtime_suspend(dev);
 	blk_post_runtime_suspend(sdev->request_queue, err);
 
 	return err;
 }
 
-static int sdev_runtime_suspend(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-	int (*cb)(struct device *) = pm ? pm->runtime_suspend : NULL;
-	struct scsi_device *sdev = to_scsi_device(dev);
-	int err;
-
-	if (sdev->request_queue->dev)
-		return sdev_blk_runtime_suspend(sdev, cb);
-
-	err = scsi_dev_type_suspend(dev, cb);
-	if (err == -EAGAIN)
-		pm_schedule_suspend(dev, jiffies_to_msecs(
-					round_jiffies_up_relative(HZ/10)));
-	return err;
-}
-
 static int scsi_runtime_suspend(struct device *dev)
 {
 	int err = 0;
@@ -189,31 +173,20 @@  static int scsi_runtime_suspend(struct device *dev)
 	return err;
 }
 
-static int sdev_blk_runtime_resume(struct scsi_device *sdev,
-					int (*cb)(struct device *))
+static int sdev_runtime_resume(struct device *dev)
 {
+	struct scsi_device *sdev = to_scsi_device(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int err = 0;
 
 	blk_pre_runtime_resume(sdev->request_queue);
-	if (cb)
-		err = cb(&sdev->sdev_gendev);
+	if (pm && pm->runtime_resume)
+		err = pm->runtime_resume(dev);
 	blk_post_runtime_resume(sdev->request_queue, err);
 
 	return err;
 }
 
-static int sdev_runtime_resume(struct device *dev)
-{
-	struct scsi_device *sdev = to_scsi_device(dev);
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-	int (*cb)(struct device *) = pm ? pm->runtime_resume : NULL;
-
-	if (sdev->request_queue->dev)
-		return sdev_blk_runtime_resume(sdev, cb);
-	else
-		return scsi_dev_type_resume(dev, cb);
-}
-
 static int scsi_runtime_resume(struct device *dev)
 {
 	int err = 0;
@@ -234,14 +207,11 @@  static int scsi_runtime_idle(struct device *dev)
 	/* Insert hooks here for targets, hosts, and transport classes */
 
 	if (scsi_is_sdev_device(dev)) {
-		struct scsi_device *sdev = to_scsi_device(dev);
-
-		if (sdev->request_queue->dev) {
-			pm_runtime_mark_last_busy(dev);
-			pm_runtime_autosuspend(dev);
-			return -EBUSY;
-		}
+		pm_runtime_mark_last_busy(dev);
+		pm_runtime_autosuspend(dev);
+		return -EBUSY;
 	}
+
 	return 0;
 }
 
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 119d67f..40d8592 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -161,14 +161,10 @@  static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
 		goto out;
 	cd = scsi_cd(disk);
 	kref_get(&cd->kref);
-	if (scsi_device_get(cd->device))
-		goto out_put;
-	if (!scsi_autopm_get_device(cd->device))
-		goto out;
-
- out_put:
-	kref_put(&cd->kref, sr_kref_release);
-	cd = NULL;
+	if (scsi_device_get(cd->device)) {
+		kref_put(&cd->kref, sr_kref_release);
+		cd = NULL;
+	}
  out:
 	mutex_unlock(&sr_ref_mutex);
 	return cd;
@@ -180,7 +176,6 @@  static void scsi_cd_put(struct scsi_cd *cd)
 
 	mutex_lock(&sr_ref_mutex);
 	kref_put(&cd->kref, sr_kref_release);
-	scsi_autopm_put_device(sdev);
 	scsi_device_put(sdev);
 	mutex_unlock(&sr_ref_mutex);
 }
@@ -558,8 +553,6 @@  static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 	void __user *argp = (void __user *)arg;
 	int ret;
 
-	scsi_autopm_get_device(cd->device);
-
 	mutex_lock(&sr_mutex);
 
 	/*
@@ -591,7 +584,6 @@  static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 
 out:
 	mutex_unlock(&sr_mutex);
-	scsi_autopm_put_device(cd->device);
 	return ret;
 }
 
@@ -599,17 +591,11 @@  static unsigned int sr_block_check_events(struct gendisk *disk,
 					  unsigned int clearing)
 {
 	struct scsi_cd *cd = scsi_cd(disk);
-	unsigned int ret;
 
-	if (atomic_read(&cd->device->disk_events_disable_depth) == 0) {
-		scsi_autopm_get_device(cd->device);
-		ret = cdrom_check_events(&cd->cdi, clearing);
-		scsi_autopm_put_device(cd->device);
-	} else {
-		ret = 0;
-	}
+	if (atomic_read(&cd->device->disk_events_disable_depth))
+		return 0;
 
-	return ret;
+	return cdrom_check_events(&cd->cdi, clearing);
 }
 
 static int sr_block_revalidate_disk(struct gendisk *disk)
@@ -617,8 +603,6 @@  static int sr_block_revalidate_disk(struct gendisk *disk)
 	struct scsi_cd *cd = scsi_cd(disk);
 	struct scsi_sense_hdr sshdr;
 
-	scsi_autopm_get_device(cd->device);
-
 	/* if the unit is not ready, nothing more to do */
 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 		goto out;
@@ -626,7 +610,6 @@  static int sr_block_revalidate_disk(struct gendisk *disk)
 	sr_cd_check(&cd->cdi);
 	get_sectorsize(cd);
 out:
-	scsi_autopm_put_device(cd->device);
 	return 0;
 }
 
@@ -747,6 +730,12 @@  static int sr_probe(struct device *dev)
 	if (register_cdrom(&cd->cdi))
 		goto fail_put;
 
+	/*
+	 * Initialize block layer runtime PM stuffs before the
+	 * periodic event checking request gets started in add_disk.
+	 */
+	blk_pm_runtime_init(sdev->request_queue, dev);
+
 	dev_set_drvdata(dev, cd);
 	disk->flags |= GENHD_FL_REMOVABLE;
 	add_disk(disk);