diff options
| author |   Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2019-08-30 13:56:14 +1000 |
|---|---|---|
| committer |   Felipe Balbi <felipe.balbi@linux.intel.com> | 2019-08-30 09:27:33 +0300 |
| commit | 18a93cd38be3e69ac5b067c570a78a369b79e31d (patch) | |
| tree | a1f6264e618b6fcb15b97074733b9e5fc8e18148 /drivers/usb | |
| parent | usb: gadget: net2280: Move all "ll" registers in one structure (diff) | |
| download | linux-dev-18a93cd38be3e69ac5b067c570a78a369b79e31d.tar.xz linux-dev-18a93cd38be3e69ac5b067c570a78a369b79e31d.zip | |
usb: gadget: net2280: Add workaround for AB chip Errata 11
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@kernel.crashing.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/gadget/udc/net2280.c | 10 |
1 files changed, 10 insertions, 0 deletions
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 @@ -2270,6 +2270,16 @@ static void usb_reinit_338x(struct net2280 *dev) 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 * link robustness with various hosts and hubs. |