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| author | Andre Przywara <andre.przywara@amd.com> | 2012-09-04 10:28:03 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-09-09 22:04:34 +0200 |
| commit | acd316248205d553594296f1895ba5196b89ffcc (patch) | |
| tree | c056ba67e8666867ee5f4c9acc7d665f1c0dbd61 /drivers/cpufreq/acpi-cpufreq.c | |
| parent | acpi-cpufreq: Add support for modern AMD CPUs (diff) | |
| download | linux-acd316248205d553594296f1895ba5196b89ffcc.tar.xz linux-acd316248205d553594296f1895ba5196b89ffcc.zip | |
acpi-cpufreq: Add quirk to disable _PSD usage on all AMD CPUs
To workaround some Windows specific behavior, the ACPI _PSD table
on AMD desktop boards advertises all cores as dependent, meaning
that they all can only use the same P-state. acpi-cpufreq strictly
obeys this description, instantiating one CPU only and symlinking
the others. But the hardware can have distinct frequencies for each
core and powernow-k8 did it that way.
So, in order to use the hardware to its full potential and keep the
original powernow-k8 behavior, lets override the _PSD table setting
on AMD hardware.
We use the siblings table, as it matches the current hardware
behavior.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/cpufreq/acpi-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/acpi-cpufreq.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index 067a61f06bb5..70e717305c29 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -51,6 +51,8 @@ MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski"); MODULE_DESCRIPTION("ACPI Processor P-States Driver"); MODULE_LICENSE("GPL"); +#define PFX "acpi-cpufreq: " + enum { UNDEFINED_CAPABLE = 0, SYSTEM_INTEL_MSR_CAPABLE, @@ -586,6 +588,14 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) policy->shared_type = CPUFREQ_SHARED_TYPE_ALL; cpumask_copy(policy->cpus, cpu_core_mask(cpu)); } + + if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) { + cpumask_clear(policy->cpus); + cpumask_set_cpu(cpu, policy->cpus); + cpumask_copy(policy->related_cpus, cpu_sibling_mask(cpu)); + policy->shared_type = CPUFREQ_SHARED_TYPE_HW; + pr_info_once(PFX "overriding BIOS provided _PSD data\n"); + } #endif /* capability check */ |