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>
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 463b024..f32010b 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -60,6 +60,11 @@
* 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 @@
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 @@
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