Date: Mon, 25 Jul 2011 00:54:18 +0900 From: Taku YAMAMOTO <taku@tackymt.homeip.net> To: freebsd-acpi@FreeBSD.org Subject: Fw: Follow-up: (Missing) power states of an Atom N455-based netbook Message-ID: <20110725005418.4f9711fd.taku@tackymt.homeip.net>
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For those interested in the native Cx patch:
in short, I found that a call to ACPI_ENABLE_IRQS(); , right before return,
was missing in the C1 code path.
Begin forwarded message:
Date: Sun, 24 Jul 2011 18:02:19 +0900
From: Taku YAMAMOTO <taku@tackymt.homeip.net>
To: Jung-uk Kim <jkim@FreeBSD.org>
Cc: avg@FreeBSD.org
Subject: Follow-up: (Missing) power states of an Atom N455-based netbook
On Sat, 23 Jul 2011 04:25:13 +0900
Taku YAMAMOTO <taku@tackymt.homeip.net> wrote:
> I've managed to update my X60 to the r224243 and your acpi_cx_native2.diff
> still works nicely.
Actually it didn't generally, though it happened to work in a way I usually
use. Putting single kenv (like boot_single=YES) was enough to break.
And, I finally found a small but fatal bug.
We (assuming acpi_cx_native2.patch already applied) have the following code
in acpi_cpu_idle():
if (cx_next->type == ACPI_STATE_C1) {
AcpiHwRead(&start_time, &AcpiGbl_FADT.XPmTimerBlock);
acpi_cpu_idle_cx(cx_next, sc->cpu_cx_native);
AcpiHwRead(&end_time, &AcpiGbl_FADT.XPmTimerBlock);
end_time = PM_USEC(acpi_TimerDelta(end_time, start_time));
if (curthread->td_critnest == 0)
end_time = min(end_time, 500000 / hz);
sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + end_time) / 4;
return;
}
In this code, however, interrupts are left disabled after the return when we
are using MWAIT.
Inserting ACPI_ENABLE_IRQS(); before the return statement is the way to fix.
Hope this helps.
--
-|-__ YAMAMOTO, Taku
| __ < <taku@tackymt.homeip.net>
- A chicken is an egg's way of producing more eggs. -
--
-|-__ 山本 拓 / YAMAMOTO, Taku
| __ < <taku@tackymt.homeip.net>
- A chicken is an egg's way of producing more eggs. -
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