From 36e200f0199192c48e563bd365fe6e88e4cb0862 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 16 Jul 2026 15:56:37 +0100 Subject: [PATCH] perf/arm_cspmu: Make IRQ more optional If we have 64-bit counters, we can reasonably assume we'll never have to handle an overflow before the end of the universe (since we're a system PMU with no sampling). Thus even if firmware does specify an IRQ, we can still continue in the event of being unable to request it. This can help systems where IRQs cannot be claimed exclusively, or are broken in other ways. Reviewed-by: Ilkka Koskinen Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- drivers/perf/arm_cspmu/arm_cspmu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c index d641119c2df4..1074225ff450 100644 --- a/drivers/perf/arm_cspmu/arm_cspmu.c +++ b/drivers/perf/arm_cspmu/arm_cspmu.c @@ -1256,8 +1256,11 @@ static int arm_cspmu_device_probe(struct platform_device *pdev) return ret; ret = arm_cspmu_request_irq(cspmu); - if (ret) - return ret; + if (ret) { + if (counter_size(cspmu) < 64) + return ret; + dev_info(cspmu->dev, "Continuing without IRQ\n"); + } ret = arm_cspmu_get_cpus(cspmu); if (ret)