diff options
| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2005-10-23 16:31:00 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2005-12-01 01:30:35 -0500 |
| commit | 05131ecc99ea9da7f45ba3058fe8a2c1d0ceeab8 (patch) | |
| tree | dec76975406874cf677d6391302f42a6da55ac38 /arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c | |
| parent | d2149b542382bfc206cb28485108f6470c979566 (diff) | |
[ACPI] Avoid BIOS inflicted crashes by evaluating _PDC only once
Linux invokes the AML _PDC method (Processor Driver Capabilities)
to tell the BIOS what features it can handle. While the ACPI
spec says nothing about the OS invoking _PDC multiple times,
doing so with changing bits seems to hopelessly confuse the BIOS
on multiple platforms up to and including crashing the system.
Factor out the _PDC invocation so Linux invokes it only once.
http://bugzilla.kernel.org/show_bug.cgi?id=5483
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c')
| -rw-r--r-- | arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c | 12 |
1 files changed, 0 insertions, 12 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c index edb9873e27e..d93023438c4 100644 --- a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c +++ b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c @@ -364,22 +364,10 @@ static struct acpi_processor_performance p; */ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy) { - union acpi_object arg0 = {ACPI_TYPE_BUFFER}; - u32 arg0_buf[3]; - struct acpi_object_list arg_list = {1, &arg0}; unsigned long cur_freq; int result = 0, i; unsigned int cpu = policy->cpu; - /* _PDC settings */ - arg0.buffer.length = 12; - arg0.buffer.pointer = (u8 *) arg0_buf; - arg0_buf[0] = ACPI_PDC_REVISION_ID; - arg0_buf[1] = 1; - arg0_buf[2] = ACPI_PDC_EST_CAPABILITY_SMP_MSR; - - p.pdc = &arg_list; - /* register with ACPI core */ if (acpi_processor_register_performance(&p, cpu)) { dprintk(KERN_INFO PFX "obtaining ACPI data failed\n"); |