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 pluged 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 on reset, 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. I don't know if this is actually the right fix, but it seems to work well. Feedback would be greatly appreciated! Cc: Wei Xu <[email protected]> Cc: Guodong Xu <[email protected]> Cc: Chen Yu <[email protected]> Cc: Amit Pundir <[email protected]> Cc: Rob Herring <[email protected]> Cc: Mark Rutland <[email protected]> Cc: John Youn <[email protected]> Cc: Douglas Anderson <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: [email protected] Signed-off-by: John Stultz <[email protected]> --- drivers/usb/dwc2/gadget.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 24fbebc..5505001 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -2519,6 +2519,8 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg, /* Kill any ep0 requests as controller will be reinitialized */ kill_all_requests(hsotg, hsotg->eps_out[0], -ECONNRESET); + /* Make sure everything is disconnected */ + dwc2_hsotg_disconnect(hsotg); if (!is_usb_reset) if (dwc2_core_reset(hsotg)) -- 2.7.4
