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>
This commit is contained in:
Thomas Renninger 2007-05-18 21:59:28 -05:00 committed by Len Brown
parent e697789d64
commit 623b78c39c
1 changed files with 15 additions and 1 deletions

View File

@ -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