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authorThomas Renninger <trenn@suse.de>2007-05-18 21:59:28 -0500
committerLen Brown <len.brown@intel.com>2008-01-01 13:24:38 -0500
commit623b78c39c4525731f852072edd742cc4fba6786 (patch)
tree69310d449e923818c79639a6c54291b85d721d59 /drivers/acpi
parente697789d64f8748cb219d7f5c413c512953802cc (diff)
ACPI: add "processor.ignore_ppc" hook to workaround BIOS _PPC weirdness
There have been fixes using _PPC, which seem to unhide a problem on HP nx6125 (double cpufreq switch freezes the machine for several seconds). This one should provide a workaround for the nx6125 and for possible other machines that show any weird _PPC behaviour. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/processor_perflib.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 463b0247cbc..f32010bee4d 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -60,6 +60,11 @@ static DEFINE_MUTEX(performance_mutex);
* policy is adjusted accordingly.
*/
+static unsigned int ignore_ppc = 0;
+module_param(ignore_ppc, uint, 0644);
+MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
+ "limited by BIOS, this should help");
+
#define PPC_REGISTERED 1
#define PPC_IN_USE 2
@@ -72,6 +77,9 @@ static int acpi_processor_ppc_notifier(struct notifier_block *nb,
struct acpi_processor *pr;
unsigned int ppc = 0;
+ if (ignore_ppc)
+ return 0;
+
mutex_lock(&performance_mutex);
if (event != CPUFREQ_INCOMPATIBLE)
@@ -130,7 +138,13 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
{
- int ret = acpi_processor_get_platform_limit(pr);
+ int ret;
+
+ if (ignore_ppc)
+ return 0;
+
+ ret = acpi_processor_get_platform_limit(pr);
+
if (ret < 0)
return (ret);
else