[RFC 3/5] scsi, pm, add pm_runtime_get/put in scsi request function

From: Huang Ying
Date: Mon Feb 06 2012 - 02:32:37 EST


To support request based scsi device runtime PM.

Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 10 ++++++++++
drivers/scsi/scsi_pm.c | 30 ++++++++++++++++++++++++++++++
drivers/scsi/scsi_priv.h | 8 ++++++++
3 files changed, 48 insertions(+)

--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -314,6 +314,8 @@ void scsi_device_unbusy(struct scsi_devi
spin_unlock(shost->host_lock);
spin_lock(sdev->request_queue->queue_lock);
sdev->device_busy--;
+ if (!sdev->device_busy)
+ scsi_autopm_put_device(sdev);
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
}

@@ -1418,6 +1420,8 @@ static void scsi_kill_request(struct req
* bump busy counts. To bump the counters, we need to dance
* with the locks as normal issue path does.
*/
+ if (!sdev->device_busy)
+ scsi_autopm_get_device_noresume(sdev);
sdev->device_busy++;
spin_unlock(sdev->request_queue->queue_lock);
spin_lock(shost->host_lock);
@@ -1520,6 +1524,10 @@ static void scsi_request_fn(struct reque
}


+ if (!sdev->device_busy) {
+ if (scsi_autopm_get_device(sdev))
+ break;
+ }
/*
* Remove the request from the request list.
*/
@@ -1600,6 +1608,8 @@ static void scsi_request_fn(struct reque
spin_lock_irq(q->queue_lock);
blk_requeue_request(q, req);
sdev->device_busy--;
+ if (sdev->device_busy == 0)
+ scsi_autopm_put_device_noidle(sdev);
out_delay:
if (sdev->device_busy == 0)
blk_delay_queue(q, SCSI_QUEUE_DELAY);
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -176,12 +176,42 @@ int scsi_autopm_get_device_sync(struct s
}
EXPORT_SYMBOL_GPL(scsi_autopm_get_device_sync);

+int scsi_autopm_get_device(struct scsi_device *sdev)
+{
+ int err;
+
+ err = pm_runtime_get(&sdev->sdev_gendev);
+ if (err < 0 && err != -EACCES && err != -EINPROGRESS &&
+ err != -EAGAIN)
+ pm_runtime_put_noidle(&sdev->sdev_gendev);
+ else
+ err = 0;
+ return err;
+}
+
+void scsi_autopm_get_device_noresume(struct scsi_device *sdev)
+{
+ pm_runtime_get_noresume(&sdev->sdev_gendev);
+}
+
void scsi_autopm_put_device_sync(struct scsi_device *sdev)
{
+ pm_runtime_mark_last_busy(&sdev->sdev_gendev);
pm_runtime_put_sync(&sdev->sdev_gendev);
}
EXPORT_SYMBOL_GPL(scsi_autopm_put_device_sync);

+void scsi_autopm_put_device(struct scsi_device *sdev)
+{
+ pm_runtime_mark_last_busy(&sdev->sdev_gendev);
+ pm_runtime_put(&sdev->sdev_gendev);
+}
+
+void scsi_autopm_put_device_noidle(struct scsi_device *sdev)
+{
+ pm_runtime_put_noidle(&sdev->sdev_gendev);
+}
+
void scsi_autopm_get_target_sync(struct scsi_target *starget)
{
pm_runtime_get_sync(&starget->dev);
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -151,11 +151,19 @@ static inline void scsi_netlink_exit(voi
extern const struct dev_pm_ops scsi_bus_pm_ops;
#endif
#ifdef CONFIG_PM_RUNTIME
+extern int scsi_autopm_get_device(struct scsi_device *);
+extern void scsi_autopm_get_device_noresume(struct scsi_device *);
+extern void scsi_autopm_put_device(struct scsi_device *);
+extern void scsi_autopm_put_device_noidle(struct scsi_device *);
extern void scsi_autopm_get_target_sync(struct scsi_target *);
extern void scsi_autopm_put_target_sync(struct scsi_target *);
extern int scsi_autopm_get_host_sync(struct Scsi_Host *);
extern void scsi_autopm_put_host_sync(struct Scsi_Host *);
#else
+extern int scsi_autopm_get_device(struct scsi_device *sdev) { return 0; }
+extern void scsi_autopm_get_device_noresume(struct scsi_device *sdev) {}
+extern void scsi_autopm_put_device(struct scsi_device *sdev) {}
+extern void scsi_autopm_put_device_noidle(struct scsi_device *sdev) {}
static inline void scsi_autopm_get_target_sync(struct scsi_target *t) {}
static inline void scsi_autopm_put_target_sync(struct scsi_target *t) {}
static inline int scsi_autopm_get_host_sync(struct Scsi_Host *h) { return 0; }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/