4.4-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 @@ -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);