[PATCH] drivers/perf: arm_pmu: make info messages more verbose

On Mon, Feb 01, 2016 at 05:43:23PM +0100, Dirk Behme wrote:

On 12.01.2016 09:22, Dirk Behme wrote:

quoted

On a big.LITTLE system e.g. with Cortex A57 and A53 in case not all cores
are online at PMU probe time we might get

hw perfevents: failed to probe PMU!
hw perfevents: failed to register PMU devices!

making it unclear which cores failed, here.

Add the name of the PMU which failed resulting in a more verbose and
helpful message

hw perfevents: armv8_cortex_a53: failed to probe PMU!
hw perfevents: armv8_cortex_a53: failed to register PMU devices!

Signed-off-by: Dirk Behme <redacted>
---
 drivers/perf/arm_pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index be3755c..fc1f06f 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c

@@ -904,7 +904,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 	}

 	if (ret) {
-		pr_info("failed to probe PMU!\n");
+		pr_info("%s: failed to probe PMU!\n", pmu->name);
 		goto out_free;
 	}

@@ -921,7 +921,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
 out_destroy:
 	cpu_pmu_destroy(pmu);
 out_free:
-	pr_info("failed to register PMU devices!\n");
+	pr_info("%s: failed to register PMU devices!\n", pmu->name);
 	kfree(pmu);
 	return ret;
 }

Any comments on this?

While this tells us that we didn't probe a particular PMU, it doesn't
tell us _why_.

We also shouldn't use pmu->name, as if we failed to find anything in the
match table, that'll be NULL. It would be better to use the full node
name from DT.

If not, how to get this applied?

You'll need to Cc the maintainer (Will Deacon). I've added him to Cc.

Thanks,
Mark.