diff options
Diffstat (limited to 'drivers/scsi/scsi_pm.c')
| -rw-r--r-- | drivers/scsi/scsi_pm.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c index d329f8b12e2b..bf8bf79e6a1f 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); |