From: John Stultz <>

[ 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 <>
Cc: Guodong Xu <>
Cc: Amit Pundir <>
Cc: Rob Herring <>
Cc: John Youn <>
Cc: Douglas Anderson <>
Cc: Chen Yu <>
Cc: Felipe Balbi <>
Cc: Greg Kroah-Hartman <>
Acked-by: John Youn <>
Signed-off-by: John Stultz <>
Signed-off-by: Felipe Balbi <>
Signed-off-by: Sasha Levin <>
 drivers/usb/dwc2/hcd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 571c21727ff9..88bd950665fa 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -1385,6 +1385,7 @@ static void dwc2_conn_id_status_change(struct work_struct 
                dwc2_core_init(hsotg, false, -1);
                spin_lock_irqsave(&hsotg->lock, flags);
+               dwc2_hsotg_disconnect(hsotg);
                dwc2_hsotg_core_init_disconnected(hsotg, false);
                spin_unlock_irqrestore(&hsotg->lock, flags);

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