From af06fba45746058ba8f983a0ac2f457a3404edba Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Wed, 5 Aug 2026 08:59:04 -0700 Subject: [PATCH] perf/cxl: Accept an overflow interrupt on MSI message number 0 cxl_pmu_probe() rejects the PMU when info->irq <= 0, but at that point the field still holds the MSI/MSI-X message number the device signals overflow on, not a Linux virq. That number is 0-based, and -1 means no interrupt support. Message number 0 is valid and pci_irq_vector() takes a 0-based index, so a compliant device signalling on the first vector fails to probe. Reject only the no-interrupt case, matching how the CXL mailbox and event interrupts handle it. Fixes: 5d7107c72796 ("perf: CXL Performance Monitoring Unit driver") Reported-by: sashiko-bot@kernel.org Closes: https://sashiko.dev/#/patchset/20260715191454.459673-1-dave@stgolabs.net?part=1 Assisted-by: Claude:claude-opus-4-8 Reviewed-by: Jonathan Cameron Reviewed-by: Davidlohr Bueso Acked-by: Richard Cheng Signed-off-by: Dave Jiang Signed-off-by: Will Deacon --- drivers/perf/cxl_pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/perf/cxl_pmu.c b/drivers/perf/cxl_pmu.c index 4b1827d74bde..e9628bc88c78 100644 --- a/drivers/perf/cxl_pmu.c +++ b/drivers/perf/cxl_pmu.c @@ -986,7 +986,7 @@ static int cxl_pmu_probe(struct device *dev) .capabilities = PERF_PMU_CAP_NO_EXCLUDE, }; - if (info->irq <= 0) + if (info->irq < 0) return -EINVAL; rc = pci_irq_vector(pdev, info->irq);