perf/arm-cmn: Fix CPU hotplug unregistration
Attempting to migrate the PMU context after we've unregistered the PMU
device, or especially if we never successfully registered it in the
first place, is a woefully bad idea. It's also fundamentally pointless
anyway. Make sure to unregister an instance from the hotplug handler
*without* invoking the teardown callback.
Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/2c221d745544774e4b07583b65b5d4d94f7e0fe4.1638530442.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index bc3cba5..400eb7f 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -1561,7 +1561,8 @@ static int arm_cmn_probe(struct platform_device *pdev)
err = perf_pmu_register(&cmn->pmu, name, -1);
if (err)
- cpuhp_state_remove_instance(arm_cmn_hp_state, &cmn->cpuhp_node);
+ cpuhp_state_remove_instance_nocalls(arm_cmn_hp_state, &cmn->cpuhp_node);
+
return err;
}
@@ -1572,7 +1573,7 @@ static int arm_cmn_remove(struct platform_device *pdev)
writel_relaxed(0, cmn->dtc[0].base + CMN_DT_DTC_CTL);
perf_pmu_unregister(&cmn->pmu);
- cpuhp_state_remove_instance(arm_cmn_hp_state, &cmn->cpuhp_node);
+ cpuhp_state_remove_instance_nocalls(arm_cmn_hp_state, &cmn->cpuhp_node);
return 0;
}