From 05131ecc99ea9da7f45ba3058fe8a2c1d0ceeab8 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Sun, 23 Oct 2005 16:31:00 -0400 Subject: [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 Signed-off-by: Len Brown --- arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c | 67 ----------------------- arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c | 12 ---- 2 files changed, 79 deletions(-) (limited to 'arch/i386/kernel/cpu/cpufreq') diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c index 871366b83b3..31ce890865d 100644 --- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -297,68 +297,6 @@ acpi_cpufreq_guess_freq ( } -/* - * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities - * of this driver - * @perf: processor-specific acpi_io_data struct - * @cpu: CPU being initialized - * - * To avoid issues with legacy OSes, some BIOSes require to be informed of - * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC - * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in - * driver/acpi/processor.c - */ -static void -acpi_processor_cpu_init_pdc_est( - struct acpi_processor_performance *perf, - unsigned int cpu, - struct acpi_object_list *obj_list - ) -{ - union acpi_object *obj; - u32 *buf; - struct cpuinfo_x86 *c = cpu_data + cpu; - dprintk("acpi_processor_cpu_init_pdc_est\n"); - - if (!cpu_has(c, X86_FEATURE_EST)) - return; - - /* Initialize pdc. It will be used later. */ - if (!obj_list) - return; - - if (!(obj_list->count && obj_list->pointer)) - return; - - obj = obj_list->pointer; - if ((obj->buffer.length == 12) && obj->buffer.pointer) { - buf = (u32 *)obj->buffer.pointer; - buf[0] = ACPI_PDC_REVISION_ID; - buf[1] = 1; - buf[2] = ACPI_PDC_EST_CAPABILITY_SMP; - perf->pdc = obj_list; - } - return; -} - - -/* CPU specific PDC initialization */ -static void -acpi_processor_cpu_init_pdc( - struct acpi_processor_performance *perf, - unsigned int cpu, - struct acpi_object_list *obj_list - ) -{ - struct cpuinfo_x86 *c = cpu_data + cpu; - dprintk("acpi_processor_cpu_init_pdc\n"); - perf->pdc = NULL; - if (cpu_has(c, X86_FEATURE_EST)) - acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list); - return; -} - - static int acpi_cpufreq_cpu_init ( struct cpufreq_policy *policy) @@ -373,9 +311,6 @@ acpi_cpufreq_cpu_init ( struct acpi_object_list arg_list = {1, &arg0}; dprintk("acpi_cpufreq_cpu_init\n"); - /* setup arg_list for _PDC settings */ - arg0.buffer.length = 12; - arg0.buffer.pointer = (u8 *) arg0_buf; data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL); if (!data) @@ -383,9 +318,7 @@ acpi_cpufreq_cpu_init ( acpi_io_data[cpu] = data; - acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list); result = acpi_processor_register_performance(&data->acpi_data, cpu); - data->acpi_data.pdc = NULL; if (result) goto err_free; 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"); -- cgit v1.2.3 From 35f652b5ef4ef145ac5514f6302b3f4cebfbbad4 Mon Sep 17 00:00:00 2001 From: Benoit Boissinot Date: Fri, 6 Jan 2006 01:31:00 -0500 Subject: [ACPI] fix acpi_cpufreq.c build warrning Signed-off-by: Benoit Boissinot Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'arch/i386/kernel/cpu/cpufreq') diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c index 31ce890865d..8a5e159d818 100644 --- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -306,10 +306,6 @@ acpi_cpufreq_cpu_init ( struct cpufreq_acpi_io *data; unsigned int result = 0; - union acpi_object arg0 = {ACPI_TYPE_BUFFER}; - u32 arg0_buf[3]; - struct acpi_object_list arg_list = {1, &arg0}; - dprintk("acpi_cpufreq_cpu_init\n"); data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL); -- cgit v1.2.3