[PATCH AUTOSEL for 4.14 119/161] ACPI: processor_perflib: Do not send _PPC change notification if not ready

Sasha Levin
2018-04-09T00:25:32Z

From: Chen Yu <yu.c.chen@intel.com>

[ Upstream commit ba1edb9a5125a617d612f98eead14b9b84e75c3a ]

The following warning was triggered after resumed from S3 -
if all the nonboot CPUs were put offline before suspend:

[ 1840.329515] unchecked MSR access error: RDMSR from 0x771 at rIP: 0xffffffff86061e3a (native_read_msr+0xa/0x30)
[ 1840.329516] Call Trace:
[ 1840.329521] __rdmsr_on_cpu+0x33/0x50
[ 1840.329525] generic_exec_single+0x81/0xb0
[ 1840.329527] smp_call_function_single+0xd2/0x100
[ 1840.329530] ? acpi_ds_result_pop+0xdd/0xf2
[ 1840.329532] ? acpi_ds_create_operand+0x215/0x23c
[ 1840.329534] rdmsrl_on_cpu+0x57/0x80
[ 1840.329536] ? cpumask_next+0x1b/0x20
[ 1840.329538] ? rdmsrl_on_cpu+0x57/0x80
[ 1840.329541] intel_pstate_update_perf_limits+0xf3/0x220
[ 1840.329544] ? notifier_call_chain+0x4a/0x70
[ 1840.329546] intel_pstate_set_policy+0x4e/0x150
[ 1840.329548] cpufreq_set_policy+0xcd/0x2f0
[ 1840.329550] cpufreq_update_policy+0xb2/0x130
[ 1840.329552] ? cpufreq_update_policy+0x130/0x130
[ 1840.329556] acpi_processor_ppc_has_changed+0x65/0x80
[ 1840.329558] acpi_processor_notify+0x80/0x100
[ 1840.329561] acpi_ev_notify_dispatch+0x44/0x5c
[ 1840.329563] acpi_os_execute_deferred+0x14/0x20
[ 1840.329565] process_one_work+0x193/0x3c0
[ 1840.329567] worker_thread+0x35/0x3b0
[ 1840.329569] kthread+0x125/0x140
[ 1840.329571] ? process_one_work+0x3c0/0x3c0
[ 1840.329572] ? kthread_park+0x60/0x60
[ 1840.329575] ? do_syscall_64+0x67/0x180
[ 1840.329577] ret_from_fork+0x25/0x30
[ 1840.329585] unchecked MSR access error: WRMSR to 0x774 (tried to write 0x0000000000000000) at rIP: 0xffffffff86061f78 (native_write_msr+0x8/0x30)
[ 1840.329586] Call Trace:
[ 1840.329587] __wrmsr_on_cpu+0x37/0x40
[ 1840.329589] generic_exec_single+0x81/0xb0
[ 1840.329592] smp_call_function_single+0xd2/0x100
[ 1840.329594] ? acpi_ds_create_operand+0x215/0x23c
[ 1840.329595] ? cpumask_next+0x1b/0x20
[ 1840.329597] wrmsrl_on_cpu+0x57/0x70
[ 1840.329598] ? rdmsrl_on_cpu+0x57/0x80
[ 1840.329599] ? wrmsrl_on_cpu+0x57/0x70
[ 1840.329602] intel_pstate_hwp_set+0xd3/0x150
[ 1840.329604] intel_pstate_set_policy+0x119/0x150
[ 1840.329606] cpufreq_set_policy+0xcd/0x2f0
[ 1840.329607] cpufreq_update_policy+0xb2/0x130
[ 1840.329610] ? cpufreq_update_policy+0x130/0x130
[ 1840.329613] acpi_processor_ppc_has_changed+0x65/0x80
[ 1840.329615] acpi_processor_notify+0x80/0x100
[ 1840.329617] acpi_ev_notify_dispatch+0x44/0x5c
[ 1840.329619] acpi_os_execute_deferred+0x14/0x20
[ 1840.329620] process_one_work+0x193/0x3c0
[ 1840.329622] worker_thread+0x35/0x3b0
[ 1840.329624] kthread+0x125/0x140
[ 1840.329625] ? process_one_work+0x3c0/0x3c0
[ 1840.329626] ? kthread_park+0x60/0x60
[ 1840.329628] ? do_syscall_64+0x67/0x180
[ 1840.329631] ret_from_fork+0x25/0x30

This is because if there's only one online CPU, the MSR_PM_ENABLE
(package wide)can not be enabled after resumed, due to
intel_pstate_hwp_enable() will only be invoked on AP's online
process after resumed - if there's no AP online, the HWP remains
disabled after resumed (BIOS has disabled it in S3). Then if
there comes a _PPC change notification which touches HWP register
during this stage, the warning is triggered.

Since we don't call acpi_processor_register_performance() when
HWP is enabled, the pr->performance will be NULL. When this is
NULL we don't need to do _PPC change notification.

Reported-by: Doug Smythies <dsmythies@telus.net>
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Yu Chen <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/acpi/processor_perflib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 18b72eec3507..c7cf48ad5cb9 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -159,7 +159,7 @@ void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
{
int ret;

- if (ignore_ppc) {
+ if (ignore_ppc || !pr->performance) {
/*
* Only when it is notification event, the _OST object
* will be evaluated. Otherwise it is skipped.
--
2.15.1