From: Sebastian Andrzej Siewior etm_probe4() holds get_online_cpus() while invoking cpuhp_setup_state_nocalls(). cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup_state_nocalls_locked() to avoid the nested call. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Mathieu Poirier Cc: linux-arm-kernel@lists.infradead.org --- drivers/hwtracing/coresight/coresight-etm4x.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -990,12 +990,12 @@ static int etm4_probe(struct amba_device dev_err(dev, "ETM arch init failed\n"); if (!etm4_count++) { - cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, - "arm/coresight4:starting", - etm4_starting_cpu, etm4_dying_cpu); - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, - "arm/coresight4:online", - etm4_online_cpu, NULL); + cpuhp_setup_state_nocalls_locked(CPUHP_AP_ARM_CORESIGHT_STARTING, + "arm/coresight4:starting", + etm4_starting_cpu, etm4_dying_cpu); + ret = cpuhp_setup_state_nocalls_locked(CPUHP_AP_ONLINE_DYN, + "arm/coresight4:online", + etm4_online_cpu, NULL); if (ret < 0) goto err_arch_supported; hp_online = ret;