[SCSI] sd: add support for runtime PM
This patch (as1399) adds runtime-PM support to the sd driver. The
support is unsophisticated: If a SCSI disk device is mounted, or if
its device file is held open, then the device will not be
runtime-suspended; otherwise it will (provided userspace gives
permission by writing "auto" to the sysfs power/control attribute).
In order to make this work, a dev_set_drvdata() call had to be moved
from sd_probe_async() to sd_probe(). Also, a few lines of code were
changed to use a local variable instead of recalculating the address
of an embedded struct device.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 8802e48..cc8a1d1 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -759,6 +759,10 @@
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.
@@ -803,6 +807,8 @@
return 0;
error_out:
+ scsi_autopm_put_device(sdev);
+error_autopm:
scsi_disk_put(sdkp);
return retval;
}
@@ -834,6 +840,8 @@
* XXX and what if there are packets in flight and this close()
* XXX is followed by a "rmmod sd_mod"?
*/
+
+ scsi_autopm_put_device(sdev);
scsi_disk_put(sdkp);
return 0;
}
@@ -2232,7 +2240,6 @@
if (sdp->removable)
gd->flags |= GENHD_FL_REMOVABLE;
- dev_set_drvdata(dev, sdkp);
add_disk(gd);
sd_dif_config_host(sdkp);
@@ -2240,6 +2247,7 @@
sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
sdp->removable ? "removable " : "");
+ scsi_autopm_put_device(sdp);
put_device(&sdkp->dev);
}
@@ -2317,14 +2325,15 @@
}
device_initialize(&sdkp->dev);
- sdkp->dev.parent = &sdp->sdev_gendev;
+ sdkp->dev.parent = dev;
sdkp->dev.class = &sd_disk_class;
- dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
+ dev_set_name(&sdkp->dev, dev_name(dev));
if (device_add(&sdkp->dev))
goto out_free_index;
- get_device(&sdp->sdev_gendev);
+ get_device(dev);
+ dev_set_drvdata(dev, sdkp);
get_device(&sdkp->dev); /* prevent release before async_schedule */
async_schedule(sd_probe_async, sdkp);
@@ -2358,8 +2367,10 @@
{
struct scsi_disk *sdkp;
- async_synchronize_full();
sdkp = dev_get_drvdata(dev);
+ scsi_autopm_get_device(sdkp->device);
+
+ async_synchronize_full();
blk_queue_prep_rq(sdkp->device->request_queue, scsi_prep_fn);
device_del(&sdkp->dev);
del_gendisk(sdkp->disk);
