Patch "usb: storage: fix runtime pm issue in usb_stor_probe2" 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

usb: storage: fix runtime pm issue in usb_stor_probe2

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:
usb-storage-fix-runtime-pm-issue-in-usb_stor_probe2.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 21:46:47 +0200
Subject: usb: storage: fix runtime pm issue in usb_stor_probe2

From: Heiner Kallweit <[email protected]>

commit a094760b9a77f81ee3cbeff323ee77c928f41106 upstream.

Since commit 71723f95463d "PM / runtime: print error when activating a child to unactive parent" I see the following error message:

scsi host2: usb-storage 1-3:1.0
scsi host2: runtime PM trying to activate child device host2 but parent

	    (1-3:1.0) is not active

Digging into it it seems to be related to the problem described in the commit message for cd998ded5c12 "i2c: designware: Prevent runtime suspend during adapter registration" as scsi_add_host also calls device_add and after the call to device_add the parent device is suspended.

Fix this by using the approach from the mentioned commit and getting the runtime pm reference before calling scsi_add_host.

---
 drivers/usb/storage/usb.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

@@ -1070,17 +1070,17 @@ int usb_stor_probe2(struct us_data *us)
 	result = usb_stor_acquire_resources(us);
 	if (result)
 		goto BadDevice;
+	usb_autopm_get_interface_no_resume(us->pusb_intf);
 	snprintf(us->scsi_name, sizeof(us->scsi_name), "usb-storage %s",
 					dev_name(&us->pusb_intf->dev));
 	result = scsi_add_host(us_to_host(us), dev);
 	if (result) {
 		dev_warn(dev,
 				"Unable to add the scsi host\n");
-		goto BadDevice;
+		goto HostAddErr;
 	}
 
 	/* Submit the delayed_work for SCSI-device scanning */
-	usb_autopm_get_interface_no_resume(us->pusb_intf);
 	set_bit(US_FLIDX_SCAN_PENDING, &us->dflags);
 
 	if (delay_use > 0)

@@ -1090,6 +1090,8 @@ int usb_stor_probe2(struct us_data *us)
 	return 0;
 
 	/* We come here if there are any problems */
+HostAddErr:
+	usb_autopm_put_interface_no_suspend(us->pusb_intf);
 BadDevice:
 	usb_stor_dbg(us, "storage_probe() failed\n");
 	release_everything(us);

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

queue-4.8/usb-storage-fix-runtime-pm-issue-in-usb_stor_probe2.patch