Re: [PATCH v5 4/7] clocksource/drivers/exynos_mct: Use percpu interrupts only on ARM64
From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: 2025-10-24 11:19:08
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On 23.10.2025 22:52, Will McVicker wrote:
From: Marek Szyprowski <m.szyprowski@samsung.com>
For some unknown reasons forcing percpu interrupts for local timers
breaks CPU hotplug for 'little' cores on legacy ARM 32bit Exynos based
machines (for example Exynos5422-based Odroid-XU3/XU4 boards). Use percpu
flag only when driver is compiled for newer ARM64 architecture.
Fixes: f3cec54ee3bf ("clocksource/drivers/exynos_mct: Set local timer interrupts as percpu")This tag doesn't make sense in this patchset. Simply squash this change with the previous one, adding the following tags: Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/all/20250827102645.1964659-1-m.szyprowski@samsung.com/ (local)
quoted hunk ↗ jump to hunk
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Peter Griffin <peter.griffin@linaro.org> Reviewed-by: Krzysztof Kozlowski <redacted> --- drivers/clocksource/exynos_mct.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index a5ef7d64b1c2..1429b9d03a58 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c@@ -597,7 +597,8 @@ static int __init exynos4_timer_interrupts(struct device_node *np, if (request_irq(mct_irq, exynos4_mct_tick_isr, IRQF_TIMER | IRQF_NOBALANCING | - IRQF_PERCPU, + (IS_ENABLED(CONFIG_ARM64) ? + IRQF_PERCPU : 0), pcpu_mevt->name, pcpu_mevt)) { pr_err("exynos-mct: cannot register IRQ (cpu%d)\n", cpu);
Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland