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[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>
This commit is contained in:
Alan Stern 2010-06-16 14:52:17 -04:00 committed by James Bottomley
parent bc4f24014d
commit 478a8a0543
1 changed files with 16 additions and 5 deletions
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21
drivers/scsi/sd.c
View File

@ -759,6 +759,10 @@ 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.
@ -803,6 +807,8 @@ 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;
}
@ -834,6 +840,8 @@ static int sd_release(struct gendisk *disk, fmode_t mode)
* 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 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
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 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
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 @@ static int sd_probe(struct device *dev)
}
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 @@ static int sd_remove(struct device *dev)
{
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);