Patch "USB: musb: fix session-bit runtime-PM quirk" has been added to the 4.13-stable tree

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

USB: musb: fix session-bit runtime-PM quirk

to the 4.13-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-musb-fix-session-bit-runtime-pm-quirk.patch
and it can be found in the queue-4.13 subdirectory.

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

From: Johan Hovold <[email protected]>
Date: Mon, 9 Oct 2017 22:46:07 -0500
Subject: USB: musb: fix session-bit runtime-PM quirk

From: Johan Hovold <[email protected]>

commit 4f190e0b9de89c4c917c3ffb3799e9d00fc534ac upstream.

The current session-bit quirk implementation does not prevent the retry counter from underflowing, something which could break runtime PM and keep the device active for a very long time (about 2^32 seconds) after a disconnect.

This notably breaks the B-device timeout case, but could potentially cause problems also when the controller is operating as an A-device.

---
 drivers/usb/musb/musb_core.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

@@ -1861,22 +1861,22 @@ static void musb_pm_runtime_check_sessio
 		MUSB_DEVCTL_HR;
 	switch (devctl & ~s) {
 	case MUSB_QUIRK_B_INVALID_VBUS_91:
-		if (musb->quirk_retries--) {
+		if (musb->quirk_retries) {
 			musb_dbg(musb,
 				 "Poll devctl on invalid vbus, assume no session");
 			schedule_delayed_work(&musb->irq_work,
 					      msecs_to_jiffies(1000));
-
+			musb->quirk_retries--;
 			return;
 		}
 		/* fall through */
 	case MUSB_QUIRK_A_DISCONNECT_19:
-		if (musb->quirk_retries--) {
+		if (musb->quirk_retries) {
 			musb_dbg(musb,
 				 "Poll devctl on possible host mode disconnect");
 			schedule_delayed_work(&musb->irq_work,
 					      msecs_to_jiffies(1000));
-
+			musb->quirk_retries--;
 			return;
 		}
 		if (!musb->session)

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

queue-4.13/usb-musb-fix-late-external-abort-on-suspend.patch queue-4.13/usb-musb-fix-session-bit-runtime-pm-quirk.patch queue-4.13/usb-serial-metro-usb-add-ms7820-device-id.patch