[SCSI] sr: use block layer runtime PM

Migrate sr to make use of block layer runtime PM. Accordingly, the
SCSI bus layer runtime PM callback is simplified as all SCSI drivers
implementing runtime PM now use the block layer's request-based
mechanism.

Note that due to the device will be polled by kernel at a constant
interval, if the autosuspend delay is set longer than the polling
interval then the device will never suspend.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 16 insertions, 46 deletions

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index af4c050ce6e4..001e9ceda4c3 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -16,6 +16,8 @@
 
 #include "scsi_priv.h"
 
+#ifdef CONFIG_PM_SLEEP
+
 static int scsi_dev_type_suspend(struct device *dev, int (*cb)(struct device *))
 {
 	int err;
@@ -43,8 +45,6 @@ static int scsi_dev_type_resume(struct device *dev, int (*cb)(struct device *))
 	return err;
 }
 
-#ifdef CONFIG_PM_SLEEP
-
 static int
 scsi_bus_suspend_common(struct device *dev, int (*cb)(struct device *))
 {
@@ -145,38 +145,22 @@ 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;
@@ -190,31 +174,20 @@ 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;
@@ -235,14 +208,11 @@ 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;
 }