Patch "scsi: configure runtime pm before calling device_add in scsi_add_host_with_dma" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

scsi: configure runtime pm before calling device_add in scsi_add_host_with_dma

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
scsi-configure-runtime-pm-before-calling-device_add-in-scsi_add_host_with_dma.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Heiner Kallweit <[email protected]>
Date: Wed, 3 Aug 2016 21:49:03 +0200
Subject: scsi: configure runtime pm before calling device_add in scsi_add_host_with_dma

From: Heiner Kallweit <[email protected]>

commit 0d5644b7d8daa3c1d91acb4367731f568c9c9469 upstream.

Runtime PM should be configured already once we call device_add. See also the description in this mail thread
https://lists.linuxfoundation.org/pipermail/linux-pm/2009-November/023198.html
or the order of calls e.g. in usb_new_device.

The changed order also helps to avoid scenarios where runtime pm for &shost->shost_gendev is activated whilst the parent is suspended, resulting in error message "runtime PM trying to activate child device hostx but parent yyy is not active".

In addition properly reverse the runtime pm calls in the error path.

---
 drivers/scsi/hosts.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

@@ -246,10 +246,6 @@ int scsi_add_host_with_dma(struct Scsi_H
 
 	shost->dma_dev = dma_dev;
 
-	error = device_add(&shost->shost_gendev);
-	if (error)
-		goto out_destroy_freelist;
-
 	/*
 	 * Increase usage count temporarily here so that calling
 	 * scsi_autopm_put_host() will trigger runtime idle if there is

@@ -260,6 +256,10 @@ int scsi_add_host_with_dma(struct Scsi_H
 	pm_runtime_enable(&shost->shost_gendev);
 	device_enable_async_suspend(&shost->shost_gendev);
 
+	error = device_add(&shost->shost_gendev);
+	if (error)
+		goto out_destroy_freelist;
+
 	scsi_host_set_state(shost, SHOST_RUNNING);
 	get_device(shost->shost_gendev.parent);
 

@@ -309,6 +309,10 @@ int scsi_add_host_with_dma(struct Scsi_H
  out_del_gendev:
 	device_del(&shost->shost_gendev);
  out_destroy_freelist:
+	device_disable_async_suspend(&shost->shost_gendev);
+	pm_runtime_disable(&shost->shost_gendev);
+	pm_runtime_set_suspended(&shost->shost_gendev);
+	pm_runtime_put_noidle(&shost->shost_gendev);
 	scsi_destroy_command_freelist(shost);
  out_destroy_tags:
 	if (shost_use_blk_mq(shost))

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/scsi-configure-runtime-pm-before-calling-device_add-in-scsi_add_host_with_dma.patch