Commit fc30c4bb authored Jan 23, 2017 by John Stultz Committed by Felipe Balbi Jan 24, 2017

usb: dwc2: Workaround case where GOTGCTL state is wrong



When removing a USB-A to USB-otg adapter cable, we get a change status
irq, and then in dwc2_conn_id_status_change, we erroneously see the
GOTGCTL_CONID_B flag set. This causes us to get stuck in the
"while (!dwc2_is_device_mode(hsotg))" loop, spitting out "Waiting for
Peripheral Mode, Mode=Host" warnings until it fails out many seconds
later.

This patch works around the issue by re-reading the GOTGCTL state to
check if the GOTGCTL_CONID_B is still set and if not restarting the
change status logic.

Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Guodong Xu <guodong.xu@linaro.org>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: John Youn <johnyoun@synopsys.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Chen Yu <chenyu56@huawei.com>
Cc: Vardan Mikayelyan <mvardan@synopsys.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Reviewed-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

parent 6e6360b6

drivers/usb/dwc2/hcd.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -3237,6 +3237,14 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
		dwc2_is_host_mode(hsotg) ? "Host" :
		"Peripheral");
		msleep(20);
		/*
		* Sometimes the initial GOTGCTRL read is wrong, so
		* check it again and jump to host mode if that was
		* the case.
		*/
		gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
		if (!(gotgctl & GOTGCTL_CONID_B))
		goto host;
		if (++count > 250)
		break;
		}
		@@ -3251,6 +3259,7 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
		spin_unlock_irqrestore(&hsotg->lock, flags);
		dwc2_hsotg_core_connect(hsotg);
		} else {
		host:
		/* A-Device connector (Host Mode) */
		dev_dbg(hsotg->dev, "connId A\n");
		while (!dwc2_is_host_mode(hsotg)) {

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