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powercap: intel_rapl_tpmi: Handle PMU registration failure during probe

PATCH Superseded Sumeet Pawnikar 2 participants 2 messages Jul 19 – Jul 23 Power management core

v2 of 3 Superseded Latest is v3 →

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Sumeet Pawnikar

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#0 lore raw

PATCH v2 1/1 powercap: intel_rapl_tpmi: Handle PMU registration failure during probe

intel_rapl_tpmi_probe() invokes rapl_package_add_pmu() but ignores its return value, so a PMU registration failure would leave the driver reporting probe success despite the PMU being absent, with no log trace.

Since PMU registration is an optional auxiliary feature for perf energy counters, its failure should not break the primary powercap functionality. Check the return value and log a warning to ensure graceful degradation.

Fixes 963a9ad3c589 ("powercap: intel_rapl_tpmi: Enable PMU support")
Signed-off-by Sumeet Pawnikar <[email protected]>

---
v1->v2:
* Since PMU registration is an optional auxiliary feature here, treat it's failure as a non fatal error and log a warning and continue, similar to other RAPL drivers like intel_rapl_msr, to ensure graceful degradation (Based on Sashiko feedback:
https://sashiko.dev/#/patchset/20260515184250.228062-1-sumeet4linux%40gmail.com)
* Add Fixes tag in changelog.

---
 drivers/powercap/intel_rapl_tpmi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/powercap/intel_rapl_tpmi.c +4 -1
index 7f41491d9cd1..078a85158ce4 100644
@@ -414,7 +414,10 @@ static int intel_rapl_tpmi_probe(struct auxiliary_device *auxdev,
 		goto err;
 	}
 
-	rapl_package_add_pmu(trp->rp);
+	ret = rapl_package_add_pmu(trp->rp);
+	if (ret)
+		dev_warn(&auxdev->dev, "Failed to add RAPL PMU for Package%d, %ld\n",
+			info->package_id, ret);
 
 	auxiliary_set_drvdata(auxdev, trp);
Signature · 1 line
2.43.0
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#1 lore raw
Quoted 29 lines · Sumeet Pawnikar

intel_rapl_tpmi_probe() invokes rapl_package_add_pmu() but ignores its return value, so a PMU registration failure would leave the driver reporting probe success despite the PMU being absent, with no log trace.

Since PMU registration is an optional auxiliary feature for perf energy counters, its failure should not break the primary powercap functionality. Check the return value and log a warning to ensure graceful degradation.

Fixes 963a9ad3c589 ("powercap: intel_rapl_tpmi: Enable PMU support")
Signed-off-by Sumeet Pawnikar <[email protected]>

---
v1->v2:
* Since PMU registration is an optional auxiliary feature here, treat it's failure as a non fatal error and log a warning and continue, similar to other RAPL drivers like intel_rapl_msr, to ensure graceful degradation (Based on Sashiko feedback:
https://sashiko.dev/#/patchset/20260515184250.228062-1-sumeet4linux%40gmail.com)
* Add Fixes tag in changelog.

---
 drivers/powercap/intel_rapl_tpmi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/powercap/intel_rapl_tpmi.c +0 -0
index 7f41491d9cd1..078a85158ce4 100644

drivers/powercap/intel_rapl_tpmi.c static int intel_rapl_tpmi_probe(struct auxiliary_device *auxdev, · line 420

Quoted 8 lines
drivers/powercap/intel_rapl_tpmi.c +4 -1
@@ -414,7 +414,10 @@ static int intel_rapl_tpmi_probe(struct auxiliary_device *auxdev,
                goto err;
        }
 
-       rapl_package_add_pmu(trp->rp);
+       ret = rapl_package_add_pmu(trp->rp);
+       if (ret)
+               dev_warn(&auxdev->dev, "Failed to add RAPL PMU for Package%d, %ld\n",
+                       info->package_id, ret);

Please fix the format string as per the Sashiko comment at:

https://sashiko.dev/#/patchset/20260719085100.145555-1-sumeet4linux%40gmail.com

drivers/powercap/intel_rapl_tpmi.c static int intel_rapl_tpmi_probe(struct auxiliary_device *auxdev,

Quoted 3 lines
drivers/powercap/intel_rapl_tpmi.c +0 -1
        auxiliary_set_drvdata(auxdev, trp);
 
--

Thanks!