path: root/arch/arm/lib
diff options
authorNicolas Pitre <nicolas.pitre@linaro.org>2013-02-18 16:36:13 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-02-21 13:25:36 +0000
commit70264367a243a68b1d5636ffb570183449803cbe (patch)
treed5ab3e7434c916f97b2e22fee6dd48c7cc9c416c /arch/arm/lib
parent7c4e9ced424be4d36df6a3e3825763e97ee97607 (diff)
ARM: 7653/2: do not scale loops_per_jiffy when using a constant delay clock
When udelay() is implemented using an architected timer, it is wrong to scale loops_per_jiffy when changing the CPU clock frequency since the timer clock remains constant. The lpj should probably become an implementation detail relevant to the CPU loop based delay routine only and more confined to it. In the mean time this is the minimal fix needed to have expected delays with the timer based implementation when cpufreq is also in use. Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Liviu Dudau <Liviu.Dudau@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib')
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c
index 0dc53854a5d8..6b93f6a1a3c7 100644
--- a/arch/arm/lib/delay.c
+++ b/arch/arm/lib/delay.c
@@ -77,6 +77,7 @@ void __init register_current_timer_delay(const struct delay_timer *timer)
arm_delay_ops.delay = __timer_delay;
arm_delay_ops.const_udelay = __timer_const_udelay;
arm_delay_ops.udelay = __timer_udelay;
+ arm_delay_ops.const_clock = true;
delay_calibrated = true;
} else {
pr_info("Ignoring duplicate/late registration of read_current_timer delay\n");