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 4.9-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-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sun Mar 18 16:55:33 CET 2018 From: John Stultz <john.stultz@xxxxxxxxxx> Date: Mon, 13 Feb 2017 20:08:08 -0800 Subject: usb: dwc2: Make sure we disconnect the gadget state From: John Stultz <john.stultz@xxxxxxxxxx> [ 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. Cc: Wei Xu <xuwei5@xxxxxxxxxxxxx> Cc: Guodong Xu <guodong.xu@xxxxxxxxxx> Cc: Amit Pundir <amit.pundir@xxxxxxxxxx> Cc: Rob Herring <robh+dt@xxxxxxxxxx> Cc: John Youn <johnyoun@xxxxxxxxxxxx> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx> Cc: Chen Yu <chenyu56@xxxxxxxxxx> Cc: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: linux-usb@xxxxxxxxxxxxxxx Acked-by: John Youn <johnyoun@xxxxxxxxxxxx> Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/dwc2/hcd.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -3220,6 +3220,7 @@ static void dwc2_conn_id_status_change(s dwc2_core_init(hsotg, false); 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 john.stultz@xxxxxxxxxx are queue-4.9/usb-dwc2-make-sure-we-disconnect-the-gadget-state.patch queue-4.9/sysrq-reset-the-watchdog-timers-while-displaying-high-resolution-timers.patch queue-4.9/timers-sched_clock-update-timeout-for-clock-wrap.patch