On 2/7/2023 5:10 PM, Thinh Nguyen wrote:
On Tue, Feb 07, 2023, Elson Serrao wrote:
On 2/6/2023 4:48 PM, Thinh Nguyen wrote:
+static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async)
{
int retries;
@@ -2296,9 +2309,14 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
link_state = DWC3_DSTS_USBLNKST(reg);
switch (link_state) {
+ case DWC3_LINK_STATE_U3: /* in HS, means SUSPEND */
It's also possible to do remote wakeup in L1 for highspeed.
The rw_configured flag here is in context of triggering remote wakeup from
bus suspend only.
The remote wakeup setting for l1 in HighSpeed is controlled through LPM
token and overrides/ignores the config desc bmAttributes wakeup bit.
Section 4.1 of USB2_LinkPowerMangement_ECN[final] spec "The host system sets the Remote Wake Flag parameter in this request to
enable or disable the addressed device
for remote wake from L1. The value of this flag will temporarily (while in
L1) override the current setting of the
Remote Wake feature settable by the standard Set/ClearFeature() commands
defined in Universal Serial Bus Specification, revision 2.0, Chapter 9."
Please let me know if I am missing something.
It overrides the setting of the SetFeature request, not the device
configuration.
The rw_configured reflects the user configuration. Whether the host
tries to enable the remote wakeup through SetFeature request or LPM
token, the device should operate within the user configuration
limitation.
If the configuration indicates that it doesn't support remote wakeup, we
should prevent unexpected behavior from the device. For simplicity, we
can just return failure to wakeup for all states.
Thanks,
Thinh
L1 entry/exit is HW controlled and the remote wakeup is
conditional.(Section 7.1/Table7.2 of dwc3 data book). Even though we
block it from
SW the l1 exit will still happen from HW point of view.
To correlate the user configuration with LPM token, I experimented by
disabling the wakeup bit in the bmAtrributes, but I still see remote
wakeup bit being set in the LPM token. From the observation it seems
like there is no correlation between the wakeup bit in the bmAtrributes
and the wakeup bit in the LPM token.
Regards
Elson
