Patchwork [3/4] scsi: pm: add may_power_off flag

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Submitter Aaron Lu
Date Aug. 30, 2012, 6:40 a.m.
Message ID <>
Download mbox | patch
Permalink /patch/180803/
State Not Applicable
Delegated to: David Miller
Headers show


Aaron Lu - Aug. 30, 2012, 6:40 a.m.
Add a new flag may_power_off for scsi device, it gives the user a chance
to control when the device is runtime suspended, can we remove its power
if possible.

I'm planning using this flag for sr and sd.

For sr, if user set 0 to may_power_off, we will disable runtime suspend
for ODD, since runtime suspend for ODD is wholly for zero power ODD, if
we can't power off the ODD, there is no meaning to do runtime PM on it.

For sd, if user set 0 to may_power_off, we will not power off the device
when it is runtime suspended.

Signed-off-by: Aaron Lu <>
 include/scsi/scsi_device.h | 1 +
 1 file changed, 1 insertion(+)


diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 9895f69..ad7cb68 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -156,6 +156,7 @@  struct scsi_device {
 	unsigned is_visible:1;	/* is the device visible in sysfs */
 	unsigned can_power_off:1; /* Device supports runtime power off */
 	unsigned wce_default_on:1;	/* Cache is ON by default */
+	unsigned may_power_off:1;	/* power off is allowed by user */
 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
 	struct list_head event_list;	/* asserted events */