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 <xuw...@hisilicon.com>
Cc: Guodong Xu <guodong...@linaro.org>
Cc: Chen Yu <cheny...@huawei.com>
Cc: Amit Pundir <amit.pun...@linaro.org>
Cc: Rob Herring <robh...@kernel.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: John Youn <johny...@synopsys.com>
Cc: Douglas Anderson <diand...@chromium.org>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: linux-...@vger.kernel.org
Signed-off-by: John Stultz <john.stu...@linaro.org>
---
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
