From mboxrd@z Thu Jan  1 00:00:00 1970
From: mark.rutland@arm.com (Mark Rutland)
Date: Mon, 1 Feb 2016 16:49:49 +0000
Subject: [PATCH] drivers/perf: arm_pmu: make info messages more verbose
In-Reply-To: <56AF8B2B.6020705@gmail.com>
References: <1452586940-20137-1-git-send-email-dirk.behme@de.bosch.com>
 <56AF8B2B.6020705@gmail.com>
Message-ID: <20160201164948.GC20396@leverpostej>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Feb 01, 2016 at 05:43:23PM +0100, Dirk Behme wrote:
> On 12.01.2016 09:22, Dirk Behme wrote:
> >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 <dirk.behme@de.bosch.com>
> >---
> >  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.