From: Len Brown <len.brown@intel.com>
Date: Mon, 24 May 2010 18:27:44 +0000 (-0400)
Subject: ACPI: acpi_idle: touch TS_POLLING only in the non-MWAIT case
X-Git-Tag: v2.6.35-rc1~19^2~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=02cf4f9808382af7265cafc33dc86ec5875526aa;p=pandora-kernel.git

ACPI: acpi_idle: touch TS_POLLING only in the non-MWAIT case

commit d306ebc28649b89877a22158fe0076f06cc46f60
(ACPI: Be in TS_POLLING state during mwait based C-state entry)
fixed an important power & performance issue where ACPI c2 and c3 C-states
were clearing TS_POLLING even when using MWAIT (ACPI_STATE_FFH).
That bug had been causing us to receive redundant scheduling interrups
when we had already been woken up by MONITOR/MWAIT.

Following up on that...

In the MWAIT case, we don't have to subsequently
check need_resched(), as that c heck was there
for the TS_POLLING-clearing case.

Note that not only does the cpuidle calling function
already check need_resched() before calling us, the
low-level entry into monitor/mwait calls it twice --
guaranteeing that a write to the trigger address
can not go un-noticed.

Also, in this case, we don't have to set TS_POLLING
when we wake, because we never cleared it.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
---

Reading git-diff-tree failed