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Subject[PATCH v2] [SCSI] scsi_pm: set device runtime state before parent suspended
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Date
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




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