From: Arjan van de Ven <arjan@linux.intel.com>
Date: Tue, 31 Jan 2012 04:23:30 +0000 (-0800)
Subject: clocksource: Load the ACPI PM clocksource asynchronously
X-Git-Tag: v3.4-rc1~190^2~9^2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b519508298e0292e1771eecf14aaf67755adc39d;p=pandora-kernel.git

clocksource: Load the ACPI PM clocksource asynchronously

The ACPI clocksource takes quite some time to initialize,
and this increases the boot time of the kernel for a
double digit percentage. This while almost all modern
systems will be using the HPET already anyway.

This patch turns the clocksource loading into an asynchronous
operation; which means it won't hold up the boot while
still becoming available normally.

To make this work well, an udelay() had to be turned into an
usleep_range() so that on UP systems, we yield the CPU to
regular boot tasks instead of spinning.

CC: John Stultz <johnstul@us.ibm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Len Brown <lenb@kernel.org>

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---

Reading git-diff-tree failed