On 12/13/2016 11:12 AM, John Stultz wrote:
> 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
> erroniously 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.
>
> I suspect this isn't the best solution, but it seems to work
> well for me.
>
> Feedback would be greatly appreciated!
>
> Cc: Wei Xu <xuw...@hisilicon.com>
> Cc: Guodong Xu <guodong...@linaro.org>
> Cc: Amit Pundir <amit.pun...@linaro.org>
> Cc: Rob Herring <robh...@kernel.org>
> Cc: John Youn <johny...@synopsys.com>
> Cc: Douglas Anderson <diand...@chromium.org>
> Cc: Chen Yu <cheny...@huawei.com>
> Cc: Kishon Vijay Abraham I <kis...@ti.com>
> Cc: Felipe Balbi <felipe.ba...@linux.intel.com>
> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> Cc: linux-usb@vger.kernel.org
> Acked-by: John Youn <johny...@synopsys.com>
> Signed-off-by: John Stultz <john.stu...@linaro.org>
> ---
> drivers/usb/dwc2/hcd.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
> index df5a065..a3f34dd 100644
> --- a/drivers/usb/dwc2/hcd.c
> +++ b/drivers/usb/dwc2/hcd.c
> @@ -3199,7 +3199,7 @@ static void dwc2_conn_id_status_change(struct
> work_struct *work)
> dev_dbg(hsotg->dev, "gotgctl=%0x\n", gotgctl);
> dev_dbg(hsotg->dev, "gotgctl.b.conidsts=%d\n",
> !!(gotgctl & GOTGCTL_CONID_B));
> -
> +again:
> /* B-Device connector (Device Mode) */
> if (gotgctl & GOTGCTL_CONID_B) {
> /* Wait for switch to device mode */
> @@ -3210,6 +3210,9 @@ static void dwc2_conn_id_status_change(struct
> work_struct *work)
> dwc2_is_host_mode(hsotg) ? "Host" :
> "Peripheral");
> usleep_range(20000, 40000);
> + gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
> + if (!(gotgctl & GOTGCTL_CONID_B))
> + goto again;
> if (++count > 250)
> break;
> }
>
Hi John Stultz,
When it goes to ":again", it will go to else anyways. I'll suggest
alternative way to do this. Please see below.
Also you can add "Reviewed-by: Vardan Mikayelyan <mvar...@synopsys.com>"
Thanks,
Vardan.
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index b7311a6..128311b 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -3242,6 +3242,9 @@ static void dwc2_conn_id_status_change(struct
work_struct *work)
dwc2_is_host_mode(hsotg) ? "Host" :
"Peripheral");
usleep_range(20000, 40000);
+ gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
+ if (!(gotgctl & GOTGCTL_CONID_B))
+ goto host;
if (++count > 250)
break;
}
@@ -3256,6 +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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