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 <balbi@ti.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 9e878d9..7f4e6dd 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2378,6 +2378,30 @@
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 @@
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;