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 <[email protected]> Cc: Guodong Xu <[email protected]> Cc: Amit Pundir <[email protected]> Cc: Rob Herring <[email protected]> Cc: John Youn <[email protected]> Cc: Douglas Anderson <[email protected]> Cc: Chen Yu <[email protected]> Cc: Vardan Mikayelyan <[email protected]> Cc: Kishon Vijay Abraham I <[email protected]> Cc: Felipe Balbi <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: [email protected] Acked-by: John Youn <[email protected]> Reviewed-by: Vardan Mikayelyan <[email protected]> Signed-off-by: John Stultz <[email protected]> --- v2: Rework goto logic suggested by Vardan, and add a comment --- drivers/usb/dwc2/hcd.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index 911c3b3..b60307a 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -3241,6 +3241,14 @@ static void dwc2_conn_id_status_change(struct work_struct *work) dwc2_is_host_mode(hsotg) ? "Host" : "Peripheral"); usleep_range(20000, 40000); + /* + * 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; } @@ -3255,6 +3263,7 @@ 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)) { -- 2.7.4
