| Message ID | 1481612990-23409-3-git-send-email-john.stultz@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tue, Dec 13, 2016 at 4:28 AM, Vardan Mikayelyan <Vardan.Mikayelyan@synopsys.com> wrote: > 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 <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: 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 >> Acked-by: John Youn <johnyoun@synopsys.com> >> Signed-off-by: John Stultz <john.stultz@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. Sounds good. I've made the change. > Also you can add "Reviewed-by: Vardan Mikayelyan <mvardan@synopsys.com>" Thanks so much for your review! -john
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; }