From e1dadd3b0f277e59847d6b7de86ff67306bee4b1 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Tue, 25 Feb 2014 14:47:54 -0600 Subject: [PATCH] usb: dwc3: workaround: bogus hibernation events Revision 2.20a of the core has a known issue which would generate bogus hibernation events _and_ random failures on USB CV TD.9.23 test case. The suggested workaround is to ignore hibernation events which don't match currently connected speed. Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 9e878d9bc909..7f4e6dd63c00 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2378,6 +2378,30 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc, dev_vdbg(dwc->dev, "%s link %d\n", __func__, dwc->link_state); } +static void dwc3_gadget_hibernation_interrupt(struct dwc3 *dwc, + unsigned int evtinfo) +{ + unsigned int is_ss = evtinfo & BIT(4); + + /** + * WORKAROUND: DWC3 revison 2.20a with hibernation support + * have a known issue which can cause USB CV TD.9.23 to fail + * randomly. + * + * Because of this issue, core could generate bogus hibernation + * events which SW needs to ignore. + * + * Refers to: + * + * STAR#9000546576: Device Mode Hibernation: Issue in USB 2.0 + * Device Fallback from SuperSpeed + */ + if (is_ss ^ (dwc->speed == USB_SPEED_SUPER)) + return; + + /* enter hibernation here */ +} + static void dwc3_gadget_interrupt(struct dwc3 *dwc, const struct dwc3_event_devt *event) { @@ -2394,6 +2418,13 @@ static void dwc3_gadget_interrupt(struct dwc3 *dwc, case DWC3_DEVICE_EVENT_WAKEUP: dwc3_gadget_wakeup_interrupt(dwc); break; + case DWC3_DEVICE_EVENT_HIBER_REQ: + if (dev_WARN_ONCE(dwc->dev, !dwc->has_hibernation, + "unexpected hibernation event\n")) + break; + + dwc3_gadget_hibernation_interrupt(dwc, event->event_info); + break; case DWC3_DEVICE_EVENT_LINK_STATUS_CHANGE: dwc3_gadget_linksts_change_interrupt(dwc, event->event_info); break; -- 2.39.5