On Fri, Jul 8, 2016 at 4:51 PM, joshua stein <j...@openbsd.org> wrote:
> If the EC fails to go into burst mode for whatever reason, the Burst
> Acknowledge byte will not be there to read, which means the status
> won't have EC_STAT_OBF, which means acpiec_wait will spin forever,
> hanging the machine.
>
> This at least gets us moving again, ignoring the failure to enter
> burst mode.
Is it truly failing to enter burst mode, or are we just not doing the
dance to enter correctly? Looks like we should be waiting for an SCI
and checking for a burst acknowledge byte?
...
> @@ -196,7 +197,10 @@ void
> acpiec_burst_enable(struct acpiec_softc *sc)
> {
> acpiec_write_cmd(sc, EC_CMD_BE);
> - acpiec_read_data(sc);
> + if (acpiec_status(sc) & (EC_STAT_BURST|EC_STAT_OBF))
> + acpiec_read_data(sc);
> + else
> + dnprintf(10, "%s: failed to enter burst mode\n", DEVNAME(sc));
> }
So if it doesn't immediately set either the burst or OBF flag then
we'll continue on without reading the data? That's going to break
systems where EC isn't always fast to respond, no?
Philip Guenther
