PATCH: ecng for 6.x and 7.x

[Nate Lawson]

Nate Lawson wrote:
> I've done some major rework on the EC driver.  This should help with
> various problems, including timeouts while checking battery status or
> temperature.  The attached patches are for 6.x and 7.x.  Please test and
> let me know if you get any new errors on dmesg or if it fixes things for
> you (especially HP/Compaq laptop owners).
> 
> If you still have problems, try setting each of these tunables
> individually and then both together (i.e., in /boot/loader.conf).  Note
> that this will be four (4) test runs total, so don't just set both and
> say it doesn't work.
> 
> debug.acpi.ec.burst="1"
> debug.acpi.ec.polled="1"
> 
> I've tested both patches on a Panasonic Y4 and UnnamedOEM laptop, no
> problems in either regular or burst mode.
> 
> 
> Commit message:
> Rewrite the EC driver event model.  The main goal is to avoid
> polling/interrupt-driven fallback and instead use polling only during
> boot and pure interrupt-driven mode after boot.  Polled mode could be
> relegated completely to a legacy role if we could enable interrupts
> during boot.  Polled mode can be forced after boot by setting
> debug.acpi.ec.polled="1", i.e. if there are timeouts.

One minor note -- power off shutdown (shutdown/halt -p) is turned into a
(safe) reboot with this patch.  I have tested the fix, which is just to
force polled mode during shutdown as well.  I don't have time to re-roll
the patch today but will send tomorrow.

Please test the patch as posted, ignoring that minor issue.  The test
results during normal use are still valid.

-- 
Nate