scsi: block: pm: Simplify resume handling
Commit 05d18ae1cc
("scsi: pm: Balance pm_only counter of request queue
during system resume") fixed a problem in the block layer's runtime-PM
code: blk_set_runtime_active() failed to call blk_clear_pm_only().
However, the commit's implementation was awkward; it forced the SCSI
system-resume handler to choose whether to call blk_post_runtime_resume()
or blk_set_runtime_active(), depending on whether or not the SCSI device
had previously been runtime suspended.
This patch simplifies the situation considerably by adding the missing
function call directly into blk_set_runtime_active() (under the condition
that the queue is not already in the RPM_ACTIVE state). This allows the
SCSI routine to revert back to its original form. Furthermore, making this
change reveals that blk_post_runtime_resume() (in its success pathway) does
exactly the same thing as blk_set_runtime_active(). The duplicate code is
easily removed by making one routine call the other.
No functional changes are intended.
Link: https://lore.kernel.org/r/20200706151436.GA702867@rowland.harvard.edu
CC: Can Guo <cang@codeaurora.org>
CC: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Родитель
df4ec2fa7a
Коммит
8f38f8e0a3
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@ -164,9 +164,8 @@ EXPORT_SYMBOL(blk_pre_runtime_resume);
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*
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* Description:
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* Update the queue's runtime status according to the return value of the
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* device's runtime_resume function. If it is successfully resumed, process
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* the requests that are queued into the device's queue when it is resuming
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* and then mark last busy and initiate autosuspend for it.
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* device's runtime_resume function. If the resume was successful, call
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* blk_set_runtime_active() to do the real work of restarting the queue.
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*
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* This function should be called near the end of the device's
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* runtime_resume callback.
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@ -175,19 +174,13 @@ void blk_post_runtime_resume(struct request_queue *q, int err)
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{
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if (!q->dev)
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return;
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spin_lock_irq(&q->queue_lock);
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if (!err) {
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q->rpm_status = RPM_ACTIVE;
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pm_runtime_mark_last_busy(q->dev);
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pm_request_autosuspend(q->dev);
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blk_set_runtime_active(q);
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} else {
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spin_lock_irq(&q->queue_lock);
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q->rpm_status = RPM_SUSPENDED;
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spin_unlock_irq(&q->queue_lock);
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}
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spin_unlock_irq(&q->queue_lock);
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if (!err)
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blk_clear_pm_only(q);
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}
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EXPORT_SYMBOL(blk_post_runtime_resume);
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@ -204,15 +197,25 @@ EXPORT_SYMBOL(blk_post_runtime_resume);
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* This function can be used in driver's resume hook to correct queue
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* runtime PM status and re-enable peeking requests from the queue. It
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* should be called before first request is added to the queue.
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*
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* This function is also called by blk_post_runtime_resume() for successful
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* runtime resumes. It does everything necessary to restart the queue.
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*/
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void blk_set_runtime_active(struct request_queue *q)
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{
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if (q->dev) {
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spin_lock_irq(&q->queue_lock);
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q->rpm_status = RPM_ACTIVE;
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pm_runtime_mark_last_busy(q->dev);
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pm_request_autosuspend(q->dev);
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spin_unlock_irq(&q->queue_lock);
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}
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int old_status;
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if (!q->dev)
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return;
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spin_lock_irq(&q->queue_lock);
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old_status = q->rpm_status;
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q->rpm_status = RPM_ACTIVE;
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pm_runtime_mark_last_busy(q->dev);
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pm_request_autosuspend(q->dev);
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spin_unlock_irq(&q->queue_lock);
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if (old_status != RPM_ACTIVE)
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blk_clear_pm_only(q);
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}
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EXPORT_SYMBOL(blk_set_runtime_active);
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@ -80,10 +80,6 @@ static int scsi_dev_type_resume(struct device *dev,
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dev_dbg(dev, "scsi resume: %d\n", err);
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if (err == 0) {
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bool was_runtime_suspended;
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was_runtime_suspended = pm_runtime_suspended(dev);
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pm_runtime_disable(dev);
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err = pm_runtime_set_active(dev);
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pm_runtime_enable(dev);
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@ -97,10 +93,8 @@ static int scsi_dev_type_resume(struct device *dev,
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*/
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if (!err && scsi_is_sdev_device(dev)) {
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struct scsi_device *sdev = to_scsi_device(dev);
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if (was_runtime_suspended)
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blk_post_runtime_resume(sdev->request_queue, 0);
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else
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blk_set_runtime_active(sdev->request_queue);
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blk_set_runtime_active(sdev->request_queue);
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}
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}
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