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clocksource/drivers/tegra: Cycles can't be 0

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Tegra's timer uses n+1 scheme for the counter, i.e. timer will fire after
one tick if 0 is loaded. The minimum and maximum numbers of oneshot ticks
are defined by clockevents_config_and_register(min, max) invocation and
the min value is set to 1 tick. Hence "cycles" value can't ever be 0,
unless it's a bug in clocksource core.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Dmitry Osipenko 2019-06-18 17:03:57 +03:00 committed by Daniel Lezcano
parent fc9babc257
commit 0ef6b01d02
1 changed files with 10 additions and 3 deletions
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13
drivers/clocksource/timer-tegra.c
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@ -56,9 +56,16 @@ static int tegra_timer_set_next_event(unsigned long cycles,
{ {
void __iomem *reg_base = timer_of_base(to_timer_of(evt)); void __iomem *reg_base = timer_of_base(to_timer_of(evt));
writel_relaxed(TIMER_PTV_EN | /*
((cycles > 1) ? (cycles - 1) : 0), /* n+1 scheme */ * Tegra's timer uses n+1 scheme for the counter, i.e. timer will
reg_base + TIMER_PTV); * fire after one tick if 0 is loaded.
*
* The minimum and maximum numbers of oneshot ticks are defined
* by clockevents_config_and_register(1, 0x1fffffff + 1) invocation
* below in the code. Hence the cycles (ticks) can't be outside of
* a range supportable by hardware.
*/
writel_relaxed(TIMER_PTV_EN | (cycles - 1), reg_base + TIMER_PTV);
return 0; return 0;
} }