[SCSI] sd: implement START/STOP management

Implement SBC START/STOP management.  sdev->mange_start_stop is added.
When it's set to one, sd STOPs the device on suspend and shutdown and
STARTs it on resume.  sdev->manage_start_stop defaults is in sdev
instead of scsi_disk cdev to allow ->slave_config() override the
default configuration but is exported under scsi_disk sysfs node as
sdev->allow_restart is.

When manage_start_stop is zero (the default value), this patch doesn't
introduce any behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>

Rejections fixed and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 3 insertions, 0 deletions

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index c86e6ce143df..b05cd3b09e6e 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -120,6 +120,7 @@ struct scsi_device {
         unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */
         unsigned no_start_on_add:1;     /* do not issue start on add */
         unsigned allow_restart:1; /* issue START_UNIT in error handler */
+        unsigned manage_start_stop:1;   /* Let HLD (sd) manage start/stop */
         unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
         unsigned select_no_atn:1;
         unsigned fix_capacity:1;        /* READ_CAPACITY is too high by 1 */
diff --git a/include/scsi/sd.h b/include/scsi/sd.h
index 82e6a84b77e6..5261488e1108 100644
--- a/include/scsi/sd.h
+++ b/include/scsi/sd.h
@@ -52,6 +52,8 @@ static void sd_rw_intr(struct scsi_cmnd * SCpnt);
 static int  sd_probe(struct device *);
 static int  sd_remove(struct device *);
 static void sd_shutdown(struct device *dev);
+static int sd_suspend(struct device *dev, pm_message_t state);
+static int sd_resume(struct device *dev);
 static void sd_rescan(struct device *);
 static int  sd_init_command(struct scsi_cmnd *);
 static int  sd_issue_flush(struct device *, sector_t *);