Messages in this thread | | | Subject | Re: [PATCH] drivers/perf: xgene_pmu: Fix uninitialized resource struct | From | Mark Salter <> | Date | Tue, 08 Sep 2020 14:37:22 -0400 |
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On Mon, 2020-09-07 at 14:50 +0100, Will Deacon wrote: > On Wed, Sep 02, 2020 at 02:27:29PM -0400, Mark Salter wrote: > > diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c > > index edac28cd25dd..fdbbd0804b92 100644 > > --- a/drivers/perf/xgene_pmu.c > > +++ b/drivers/perf/xgene_pmu.c > > @@ -1483,6 +1483,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu, > > return NULL; > > > > INIT_LIST_HEAD(&resource_list); > > + memset(&res, 0, sizeof(res)); > > rc = acpi_dev_get_resources(adev, &resource_list, > > acpi_pmu_dev_add_resource, &res); > > acpi_dev_free_resource_list(&resource_list); > > Hmm, to be honest, I'm not sure we should be calling devm_ioremap_resource() > at all here. The resource is clearly bogus, even with this change: the name > and the resource hierarchy pointers will all be NULL. I think it would be > better to follow the TX2 PMU driver (drivers/perf/thunderx2_pmu.c) which > appears to assign the resource directly in tx2_uncore_pmu_init_dev(). > > Is there a reason we can't do that? > > Will >
There's no difference between xgene and tx2 wrt resouce name/hierarchy. They both call devm_ioresource_remap() which ends up setting the name and hierarchy. The difference is that xgene calls acpi_dev_resource_memory() directly from the acpi_dev_get_resources() callback. TX2 doesn't use such a callback and in that case, acpi_dev_resource_memory() gets called with a zeroed struct.
That said, changing xgene to avoid the callback like TX2 does would fix the problem as well. If you'd rather go that route, I can send a patch for it.
Mark
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