The errata description is: Workaround for Default Duration of LFPS Handshake Signaling for Device-Initiated U1 Exit is too short. The default duration of the LFPS handshake generated by USB3380 for a device-initiated U1-exit may not be long enough for certain SuperSpeed downstream ports (SuperSpeed hubs/hosts) to recognize. This could lead to USB3380 entering the recovery state pre-maturely and ending up in the SS.Inactive state. I have observed various enumeration failures, seemingly related to lost transactions or SETUP status phases on modern hosts (typically thunderbolt capable systems) without this workaround. Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/udc/net2280.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c index e0191146ba22..51efee21915f 100644 --- a/drivers/usb/gadget/udc/net2280.c +++ b/drivers/usb/gadget/udc/net2280.c @@ -2269,6 +2269,16 @@ static void usb_reinit_338x(struct net2280 *dev) val |= 0x3 << HOT_RX_RESET_TS2; writel(val, &dev->llregs->ll_tsn_counters_3); + /* + * AB errata. Errata 11. Workaround for Default Duration of LFPS + * Handshake Signaling for Device-Initiated U1 Exit is too short. + * Without this, various enumeration failures observed with + * modern superspeed hosts. + */ + val = readl(&dev->llregs->ll_lfps_timers_2); + writel((val & 0xffff0000) | LFPS_TIMERS_2_WORKAROUND_VALUE, + &dev->llregs->ll_lfps_timers_2); + /* * Set Recovery Idle to Recover bit: * - On SS connections, setting Recovery Idle to Recover Fmw improves
