From: Sandipan Das sandipan.das@amd.com
[ Upstream commit ad8c91282c95f801c37812d59d2d9eba6899b384 ]
When bringing a CPU online, some of the PMC and LBR related registers are reset. The same is done when a CPU is taken offline although that is unnecessary. This currently happens in the "cpu_dead" callback which is also incorrect as the callback runs on a control CPU instead of the one that is being taken offline. This also affects hibernation and suspend to RAM on some platforms as reported in the link below.
Fixes: 21d59e3e2c40 ("perf/x86/amd/core: Detect PerfMonV2 support") Reported-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Sandipan Das sandipan.das@amd.com Signed-off-by: Ingo Molnar mingo@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: https://lore.kernel.org/r/550a026764342cf7e5812680e3e2b91fe662b5ac.170652602... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/amd/core.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 04f4b96dec6df..fd091b9dd7067 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -604,7 +604,6 @@ static void amd_pmu_cpu_dead(int cpu)
kfree(cpuhw->lbr_sel); cpuhw->lbr_sel = NULL; - amd_pmu_cpu_reset(cpu);
if (!x86_pmu.amd_nb_constraints) return;