diff options
| author | Matthew Garrett <mjg@redhat.com> | 2012-09-04 10:28:06 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-09-09 22:05:02 +0200 |
| commit | f594065faf4f9067c2283a34619fc0714e79a98d (patch) | |
| tree | c4648afdda2ad77d5ec116855525bbe0aec684db /drivers/acpi | |
| parent | powernow-k8: delay info messages until initialization has succeeded (diff) | |
| download | linux-f594065faf4f9067c2283a34619fc0714e79a98d.tar.xz linux-f594065faf4f9067c2283a34619fc0714e79a98d.zip | |
ACPI: Add fixups for AMD P-state figures
Some AMD systems may round the frequencies in ACPI tables to 100MHz
boundaries. We can obtain the real frequencies from MSRs, so add a quirk
to fix these frequencies up on AMD systems.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/processor_perflib.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index a093dc163a42..836bfe069042 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -324,6 +324,34 @@ static int acpi_processor_get_performance_control(struct acpi_processor *pr) return result; } +#ifdef CONFIG_X86 +/* + * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding + * in their ACPI data. Calculate the real values and fix up the _PSS data. + */ +static void amd_fixup_frequency(struct acpi_processor_px *px, int i) +{ + u32 hi, lo, fid, did; + int index = px->control & 0x00000007; + + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) + return; + + if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) + || boot_cpu_data.x86 == 0x11) { + rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi); + fid = lo & 0x3f; + did = (lo >> 6) & 7; + if (boot_cpu_data.x86 == 0x10) + px->core_frequency = (100 * (fid + 0x10)) >> did; + else + px->core_frequency = (100 * (fid + 8)) >> did; + } +} +#else +static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {}; +#endif + static int acpi_processor_get_performance_states(struct acpi_processor *pr) { int result = 0; @@ -379,6 +407,8 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr) goto end; } + amd_fixup_frequency(px, i); + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n", i, |