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path: root/drivers/scsi/scsi_pm.c
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Diffstat (limited to 'drivers/scsi/scsi_pm.c')
-rw-r--r--drivers/scsi/scsi_pm.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index d329f8b12e2..bf8bf79e6a1 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -49,8 +49,22 @@ static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
{
int err = 0;
- if (scsi_is_sdev_device(dev))
+ if (scsi_is_sdev_device(dev)) {
+ /*
+ * sd is the only high-level SCSI driver to implement runtime
+ * PM, and sd treats runtime suspend, system suspend, and
+ * system hibernate identically (but not system freeze).
+ */
+ if (pm_runtime_suspended(dev)) {
+ if (msg.event == PM_EVENT_SUSPEND ||
+ msg.event == PM_EVENT_HIBERNATE)
+ return 0; /* already suspended */
+
+ /* wake up device so that FREEZE will succeed */
+ pm_runtime_resume(dev);
+ }
err = scsi_dev_type_suspend(dev, msg);
+ }
return err;
}
@@ -58,8 +72,17 @@ static int scsi_bus_resume_common(struct device *dev)
{
int err = 0;
- if (scsi_is_sdev_device(dev))
+ 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);
+ }
if (err == 0) {
pm_runtime_disable(dev);