[PATCH 5.10 321/717] clocksource/drivers/arm_arch_timer: Use stable count reader in erratum sne

Greg Kroah-Hartman
2020-12-28T14:15:02Z

From: Keqian Zhu <zhukeqian1@huawei.com>

[ Upstream commit d8cc3905b8073c7cfbff94af889fa8dc71f21dd5 ]

In commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter
to access stable counters"), we separate stable and normal count reader to omit
unnecessary overhead on systems that have no timer erratum.

However, in erratum_set_next_event_tval_generic(), count reader becomes normal
reader. This converts it to stable reader.

Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters")
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201204073126.6920-2-zhukeqian1@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clocksource/arm_arch_timer.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 6c3e841801461..777d38cb39b09 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -396,10 +396,10 @@ static void erratum_set_next_event_tval_generic(const int access, unsigned long
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;

if (access == ARCH_TIMER_PHYS_ACCESS) {
- cval = evt + arch_counter_get_cntpct();
+ cval = evt + arch_counter_get_cntpct_stable();
write_sysreg(cval, cntp_cval_el0);
} else {
- cval = evt + arch_counter_get_cntvct();
+ cval = evt + arch_counter_get_cntvct_stable();
write_sysreg(cval, cntv_cval_el0);
}

--
2.27.0