From 60b234db6bf127ad0ab831c0fddb511e9bf63fe5 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 16 Jul 2026 15:56:36 +0100 Subject: [PATCH] perf/arm_cspmu: Improve sub-module error reporting When waiting for a sub-module to register, we return a bare -EPROBE_DEFER that ends up showing the end user: platform arm-cs-arch-pmu.1: deferred probe pending (no reason) wherein it's not necessarily clear that they might need to take some action to ensure the appropriate module is available to load. Let's use dev_err_probe() here so we can show exactly what we're waiting for. Similarly, in the case where something's gone horribly wrong with an already-registered module, we can use dev_WARN() to standardise the device/driver attribution rather than just open-coding "arm_cspmu". Reviewed-by: Ilkka Koskinen Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- drivers/perf/arm_cspmu/arm_cspmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c index f4f071c79263..d641119c2df4 100644 --- a/drivers/perf/arm_cspmu/arm_cspmu.c +++ b/drivers/perf/arm_cspmu/arm_cspmu.c @@ -437,13 +437,15 @@ static int arm_cspmu_init_impl_ops(struct arm_cspmu *cspmu) if (ret) module_put(match->module); } else { - WARN(1, "arm_cspmu failed to get module: %s\n", + dev_WARN(cspmu->dev, "Failed to get module: %s\n", match->module_name); ret = -EINVAL; } } else { request_module_nowait(match->module_name); - ret = -EPROBE_DEFER; + ret = dev_err_probe(cspmu->dev, -EPROBE_DEFER, + "Waiting for module %s to load\n", + match->module_name); } mutex_unlock(&arm_cspmu_lock);