Hey John,
Just wanted to send this by you, as it seems something is
slightly off with the GOTGCTL state when removing a otg adapter
cable. The following seems to work around the issue I'm seeing.
Let me know if you have any thoughts on this.
thanks
-john
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
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 143da47..6d6802a 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -3203,7 +3203,7 @@ 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 */
@@ -3219,6 +3219,9 @@ 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;
}
--
2.7.4
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