ARM: 7685/1: delay: use private ticks_per_jiffy field for timer-based delay ops
Commit 70264367a243 ("ARM: 7653/2: do not scale loops_per_jiffy when
using a constant delay clock") fixed a problem with our timer-based
delay loop, where loops_per_jiffy is scaled by cpufreq yet used directly
by the timer delay ops.
This patch fixes the problem in a more elegant way by keeping a private
ticks_per_jiffy field in the delay ops, independent of loops_per_jiffy
and therefore not subject to scaling. The loop-based delay continues to
use loops_per_jiffy directly, as it should.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c
index 6b93f6a..64dbfa5 100644
--- a/arch/arm/lib/delay.c
+++ b/arch/arm/lib/delay.c
@@ -58,7 +58,7 @@
static void __timer_const_udelay(unsigned long xloops)
{
unsigned long long loops = xloops;
- loops *= loops_per_jiffy;
+ loops *= arm_delay_ops.ticks_per_jiffy;
__timer_delay(loops >> UDELAY_SHIFT);
}
@@ -73,11 +73,13 @@
pr_info("Switching to timer-based delay loop\n");
delay_timer = timer;
lpj_fine = timer->freq / HZ;
- loops_per_jiffy = lpj_fine;
+
+ /* cpufreq may scale loops_per_jiffy, so keep a private copy */
+ arm_delay_ops.ticks_per_jiffy = lpj_fine;
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");