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| author |   Nicolas Pitre <nicolas.pitre@linaro.org> | 2013-02-18 16:36:13 +0100 |
|---|---|---|
| committer |   Russell King <rmk+kernel@arm.linux.org.uk> | 2013-02-21 13:25:36 +0000 |
| commit | 70264367a243a68b1d5636ffb570183449803cbe (patch) | |
| tree | d5ab3e7434c916f97b2e22fee6dd48c7cc9c416c /arch/arm/lib | |
| parent | ARM: 7643/1: sched: correct update_sched_clock() (diff) | |
| download | linux-dev-70264367a243a68b1d5636ffb570183449803cbe.tar.xz linux-dev-70264367a243a68b1d5636ffb570183449803cbe.zip | |
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')
| -rw-r--r-- | arch/arm/lib/delay.c | 1 |
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"); |