* [PATCH v2] [SCSI] scsi_pm: set device runtime state before parent suspended
@ 2012-07-06 4:06 Lin Ming
2012-07-06 14:24 ` Alan Stern
0 siblings, 1 reply; 3+ messages in thread
From: Lin Ming @ 2012-07-06 4:06 UTC (permalink / raw)
To: Alan Stern, James Bottomley; +Cc: linux-scsi, linux-kernel
There is a race in scsi_bus_resume_common when set device's runtime
state to active after pm_runtime_put_sync(dev->parent).
Parent device may have been suspended so pm_runtime_set_active(dev) will
fail with -EBUSY.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
---
drivers/scsi/scsi_pm.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index d4201de..dc0ad85 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -76,23 +76,24 @@ static int scsi_bus_resume_common(struct device *dev)
{
int err = 0;
- if (scsi_is_sdev_device(dev)) {
- /*
- * Parent device may have runtime suspended as soon as
- * it is woken up during the system resume.
- *
- * Resume it on behalf of child.
- */
- pm_runtime_get_sync(dev->parent);
- err = scsi_dev_type_resume(dev);
- pm_runtime_put_sync(dev->parent);
- }
+ /*
+ * Parent device may have runtime suspended as soon as
+ * it is woken up during the system resume.
+ *
+ * Resume it on behalf of child.
+ */
+ pm_runtime_get_sync(dev->parent);
+ if (scsi_is_sdev_device(dev))
+ err = scsi_dev_type_resume(dev);
if (err == 0) {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
}
+
+ pm_runtime_put_sync(dev->parent);
+
return err;
}
--
1.7.10
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] [SCSI] scsi_pm: set device runtime state before parent suspended
2012-07-06 4:06 [PATCH v2] [SCSI] scsi_pm: set device runtime state before parent suspended Lin Ming
@ 2012-07-06 14:24 ` Alan Stern
0 siblings, 0 replies; 3+ messages in thread
From: Alan Stern @ 2012-07-06 14:24 UTC (permalink / raw)
To: Lin Ming; +Cc: James Bottomley, linux-scsi, linux-kernel
On Fri, 6 Jul 2012, Lin Ming wrote:
> There is a race in scsi_bus_resume_common when set device's runtime
> state to active after pm_runtime_put_sync(dev->parent).
>
> Parent device may have been suspended so pm_runtime_set_active(dev) will
> fail with -EBUSY.
>
> Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] [SCSI] scsi_pm: set device runtime state before parent suspended
@ 2012-07-06 14:24 ` Alan Stern
0 siblings, 0 replies; 3+ messages in thread
From: Alan Stern @ 2012-07-06 14:24 UTC (permalink / raw)
To: Lin Ming; +Cc: James Bottomley, linux-scsi, linux-kernel
On Fri, 6 Jul 2012, Lin Ming wrote:
> There is a race in scsi_bus_resume_common when set device's runtime
> state to active after pm_runtime_put_sync(dev->parent).
>
> Parent device may have been suspended so pm_runtime_set_active(dev) will
> fail with -EBUSY.
>
> Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-07-06 14:24 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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