Hi Dirk,
On 03/18/2016 02:18 AM, Dirk Behme wrote:
Hi Guenter,
On 18.03.2016 07:44, Guenter Roeck wrote:
Hi,
I am seeing the attached crash when running a realview-pb-a8 image with
realview_defconfig in qemu.
bisect wasn't successful, but a commit analysis identified commit
'drivers/perf: arm_pmu: make info
messages more verbose' as the culprit. Reverting this commit fixes the
problem.
The code roughly looks as follows.
int arm_pmu_device_probe()
{
...
if (node && ..) {
} else {
}
if (ret) {
pr_info("%s: failed to probe PMU! Error %i\n",
node->full_name, ret);
goto out_free;
}
....
out_free:
pr_info("%s: failed to register PMU devices! Error %i\n",
node->full_name, ret);
....
}
Note that 'node' is dereferenced even though it was previously checked
if it is NULL.
The configuration I am testing does not use devicetree.
Can you use dev_info() instead ?
Does anything like below [1] does work for you?
If so, could you please share the output? I.e. what it prints in your non-devicetree non-pmu case?
This is what I get:
hw perfevents: probing PMU on CPU 0
armv7-pmu armv7-pmu: failed to probe PMU! Error -6
armv7-pmu armv7-pmu: failed to register PMU devices! Error -6
Another option might be to use of_node_full_name() (or even better
both dev_info() and of_node_full_name()).
Not sure though what you are looking for. '/soc/pmu_a53' doesn't
tell (me) much either, and I am not sure I understand the context
of the bug description. Why would the kernel try to initialize PMU
for a CPU which isn't online ? And if it really does, wouldn't it make
more sense to print CPU number and CPU ID instead of a devicetree
node name ?
Thanks,
Guenter
Best regards
Dirk
[1]
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 11bacc7..bda3502 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -1002,8 +1002,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
}
if (ret) {
- pr_info("%s: failed to probe PMU! Error %i\n",
- node->full_name, ret);
+ dev_info(&pdev->dev, "failed to probe PMU! Error %i\n", ret);
goto out_free;
}
@@ -1023,8 +1022,7 @@ int arm_pmu_device_probe(struct platform_device *pdev,
out_destroy:
cpu_pmu_destroy(pmu);
out_free:
- pr_info("%s: failed to register PMU devices! Error %i\n",
- node->full_name, ret);
+ dev_info(&pdev->dev, "failed to register PMU devices! Error %i\n", ret);
kfree(pmu);
return ret;
}
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