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

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

[Dirk Behme]

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;
 }
-- 
2.5.1

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

[Dirk Behme]

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?

If not, how to get this applied?

Best regards

Dirk

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

[Mark Rutland]

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.