lkml.org 
[lkml]   [2021]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 03/21] ACPI: CPPC: Check online CPUs for determining _CPC is valid
On Sun, Sep 26, 2021 at 11:06 AM Huang Rui <ray.huang@amd.com> wrote:
>
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> As this is a static check, it should be based upon what is currently
> present on the system. This makes probeing more deterministic.
>
> While local APIC flags field (lapic_flags) of cpu core in MADT table is
> 0, then the cpu core won't be enabled. In this case, _CPC won't be found
> in this core, and return back to _CPC invalid with walking through
> possible cpus (include disable cpus). This is not expected, so switch to
> check online CPUs instead.
>
> Reported-by: Jinzhou Su <Jinzhou.Su@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> Signed-off-by: Huang Rui <ray.huang@amd.com>
> ---
> drivers/acpi/cppc_acpi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index a4d4eebba1da..2efe2ba97d96 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -411,7 +411,7 @@ bool acpi_cpc_valid(void)
> struct cpc_desc *cpc_ptr;
> int cpu;
>
> - for_each_possible_cpu(cpu) {
> + for_each_online_cpu(cpu) {

Shouldn't this be for_each_present_cpu()? In case a CPU is present,
but not online when cppc_cpufreq is loaded?

> cpc_ptr = per_cpu(cpc_desc_ptr, cpu);
> if (!cpc_ptr)
> return false;
> --

\
 
 \ /
  Last update: 2021-10-19 18:53    [W:0.292 / U:8.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site