[PATCH v10 4/4] sd: change to auto suspend mode

From: Aaron Lu
Date: Wed Feb 20 2013 - 01:11:17 EST


From: Lin Ming <ming.m.lin@xxxxxxxxx>

Uses block layer runtime pm helper functions in
scsi_runtime_suspend/resume for devices that take advantage of it.

Remove scsi_autopm_* from sd open/release path and check_events path.

Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
---
drivers/scsi/scsi_pm.c | 84 ++++++++++++++++++++++++++++++++++++++++++--------
drivers/scsi/sd.c | 13 +-------
2 files changed, 72 insertions(+), 25 deletions(-)

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index 8f6b12c..90b12d9 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -144,33 +144,83 @@ 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 *))
+{
+ int err;
+
+ err = blk_pre_runtime_suspend(sdev->request_queue);
+ if (err)
+ return err;
+ if (cb)
+ err = cb(&sdev->sdev_gendev);
+ 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 ret;
+
+ if (sdev->request_queue->dev)
+ return sdev_blk_runtime_suspend(sdev, cb);
+
+ ret = scsi_dev_type_suspend(dev, cb);
+ if (err == -EAGAIN)
+ pm_schedule_suspend(dev, jiffies_to_msecs(
+ round_jiffies_up_relative(HZ/10)));
+ return ret;
+}
+
static int scsi_runtime_suspend(struct device *dev)
{
int err = 0;
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;

dev_dbg(dev, "scsi_runtime_suspend\n");
- if (scsi_is_sdev_device(dev)) {
- err = scsi_dev_type_suspend(dev,
- pm ? pm->runtime_suspend : NULL);
- if (err == -EAGAIN)
- pm_schedule_suspend(dev, jiffies_to_msecs(
- round_jiffies_up_relative(HZ/10)));
- }
+ if (scsi_is_sdev_device(dev))
+ err = sdev_runtime_suspend(dev);

/* Insert hooks here for targets, hosts, and transport classes */

return err;
}

-static int scsi_runtime_resume(struct device *dev)
+static int sdev_blk_runtime_resume(struct scsi_device *sdev,
+ int (*cb)(struct device *))
{
int err = 0;
+
+ blk_pre_runtime_resume(sdev->request_queue);
+ if (cb)
+ err = cb(&sdev->sdev_gendev);
+ 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;

dev_dbg(dev, "scsi_runtime_resume\n");
if (scsi_is_sdev_device(dev))
- err = scsi_dev_type_resume(dev, pm ? pm->runtime_resume : NULL);
+ err = sdev_runtime_resume(dev);

/* Insert hooks here for targets, hosts, and transport classes */

@@ -185,10 +235,18 @@ static int scsi_runtime_idle(struct device *dev)

/* Insert hooks here for targets, hosts, and transport classes */

- if (scsi_is_sdev_device(dev))
- err = pm_schedule_suspend(dev, 100);
- else
+ 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);
+ err = pm_runtime_autosuspend(dev);
+ } else {
+ err = pm_runtime_suspend(dev);
+ }
+ } else {
err = pm_runtime_suspend(dev);
+ }
return err;
}

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c6e2b34..5000bec 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1121,10 +1121,6 @@ static int sd_open(struct block_device *bdev, fmode_t mode)

sdev = sdkp->device;

- retval = scsi_autopm_get_device(sdev);
- if (retval)
- goto error_autopm;
-
/*
* If the device is in error recovery, wait until it is done.
* If the device is offline, then disallow any access to it.
@@ -1169,8 +1165,6 @@ static int sd_open(struct block_device *bdev, fmode_t mode)
return 0;

error_out:
- scsi_autopm_put_device(sdev);
-error_autopm:
scsi_disk_put(sdkp);
return retval;
}
@@ -1205,7 +1199,6 @@ static int sd_release(struct gendisk *disk, fmode_t mode)
* XXX is followed by a "rmmod sd_mod"?
*/

- scsi_autopm_put_device(sdev);
scsi_disk_put(sdkp);
return 0;
}
@@ -1367,14 +1360,9 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
retval = -ENODEV;

if (scsi_block_when_processing_errors(sdp)) {
- retval = scsi_autopm_get_device(sdp);
- if (retval)
- goto out;
-
sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
sshdr);
- scsi_autopm_put_device(sdp);
}

/* failed to execute TUR, assume media not present */
@@ -2839,6 +2827,7 @@ static void sd_probe_async(void *data, async_cookie_t cookie)

sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
sdp->removable ? "removable " : "");
+ blk_pm_runtime_init(sdp->request_queue, dev);
scsi_autopm_put_device(sdp);
put_device(&sdkp->dev);
}
--
1.8.1.2

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