Patch "usb: dwc2: Make sure we disconnect the gadget state" has been added to the 4.4-stable tree

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

usb: dwc2: Make sure we disconnect the gadget state

to the 4.4-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-dwc2-make-sure-we-disconnect-the-gadget-state.patch
and it can be found in the queue-4.4 subdirectory.

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

From: John Stultz <[email protected]>
Date: Mon, 13 Feb 2017 20:08:08 -0800
Subject: usb: dwc2: Make sure we disconnect the gadget state

From: John Stultz <[email protected]>

[ Upstream commit dad3f793f20fbb5c0c342f0f5a0bdf69a4d76089 ]

I had seen some odd behavior with HiKey's usb-gadget interface that I finally seemed to have chased down. Basically every other time I plugged in the OTG port, the gadget interface would properly initialize. The other times, I'd get a big WARN_ON in dwc2_hsotg_init_fifo() about the fifo_map not being clear.

Ends up if we don't disconnect the gadget state, the fifo-map doesn't get cleared properly, which causes WARN_ON messages and also results in the device not properly being setup as a gadget every other time the OTG port is connected.

So this patch adds a call to dwc2_hsotg_disconnect() in the reset path so the state is properly cleared.

With it, the gadget interface initializes properly on every plug in.

---
 drivers/usb/dwc2/hcd.c |    1 +
 1 file changed, 1 insertion(+)

@@ -1385,6 +1385,7 @@ static void dwc2_conn_id_status_change(s
 		dwc2_core_init(hsotg, false, -1);
 		dwc2_enable_global_interrupts(hsotg);
 		spin_lock_irqsave(&hsotg->lock, flags);
+		dwc2_hsotg_disconnect(hsotg);
 		dwc2_hsotg_core_init_disconnected(hsotg, false);
 		spin_unlock_irqrestore(&hsotg->lock, flags);
 		dwc2_hsotg_core_connect(hsotg);

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

queue-4.4/usb-dwc2-make-sure-we-disconnect-the-gadget-state.patch queue-4.4/sysrq-reset-the-watchdog-timers-while-displaying-high-resolution-timers.patch queue-4.4/timers-sched_clock-update-timeout-for-clock-wrap.patch