[PATCH 4.9 139/241] usb: dwc2: Make sure we disconnect the gadget state

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

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);