From 5e18e412973d6bb1804de1d4d30a891c774b006e Mon Sep 17 00:00:00 2001
From: Sudeep Holla <sudeep.holla@arm.com>
Date: Mon, 9 Jul 2018 16:45:36 +0100
Subject: [PATCH] clocksource: arm_arch_timer: Set arch_mem_timer cpumask to
cpu_possible_mask
Currently, arch_mem_timer cpumask is set to cpu_all_mask which should be
fine. However, cpu_possible_mask is more accurate and if there are other
clockevent source in the system which are set to cpu_possible_mask, then
having cpu_all_mask may result in issue.
E.g. on a platform with arm,sp804 timer with rating 300 and
cpu_possible_mask and this arch_mem_timer timer with rating 400 and
cpu_all_mask, tick_check_preferred may choose both preferred as the
cpumasks are not equal though they must be.
This issue was root caused incorrectly initially and a fix was merged as
commit 1332a9055801 ("tick: Prefer a lower rating device only if it's CPU
local device").
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/1531151136-18297-2-git-send-email-sudeep.holla@arm.com
---
drivers/clocksource/arm_arch_timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 57cb2f00fc07c..d8c7f5750cdb0 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -735,7 +735,7 @@ static void __arch_timer_setup(unsigned type,
clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
clk->name = "arch_mem_timer";
clk->rating = 400;
- clk->cpumask = cpu_all_mask;
+ clk->cpumask = cpu_possible_mask;
if (arch_timer_mem_use_virtual) {
clk->set_state_shutdown = arch_timer_shutdown_virt_mem;
clk->set_state_oneshot_stopped = arch_timer_shutdown_virt_mem;
--
GitLab