Earlier, Ingo Molnar posted a patch to make it so that the kernel would avoid
reading _PPC on his broken T60. Unfortunately, it seems that with Thomas
Renninger's patch last July to eliminate _PPC evaluations when the processor
driver loads, the kernel never actually reads _PPC at all! This is problematic
if you happen to boot your non-T60 computer in a state where the BIOS _wants_
_PPC to be something other than zero.
So, put the _PPC evaluation back into acpi_processor_get_performance_info if
ignore_ppc isn't 1.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
drivers/acpi/processor_perflib.c | 19 ++++++++++++++-----
1 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index cafb410..0b50e8e 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -150,13 +150,10 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
return 0;
}
-int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
+static int __acpi_processor_ppc_has_changed(struct acpi_processor *pr)
{
int ret;
- if (ignore_ppc)
- return 0;
-
ret = acpi_processor_get_platform_limit(pr);
if (ret < 0)
@@ -165,6 +162,14 @@ int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
return cpufreq_update_policy(pr->id);
}
+int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
+{
+ if (ignore_ppc)
+ return 0;
+
+ return __acpi_processor_ppc_has_changed(pr);
+}
+
void acpi_processor_ppc_init(void)
{
if (!cpufreq_register_notifier
@@ -348,7 +353,11 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr)
if (result)
goto update_bios;
- return 0;
+ /* We need to call _PPC once when cpufreq starts */
+ if (ignore_ppc != 1)
+ result = __acpi_processor_ppc_has_changed(pr);
+
+ return result;
/*
* Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
