Messages in this thread Patch in this message | | | Date | Wed, 15 Apr 2009 15:53:49 -0700 | From | "Darrick J. Wong" <> | Subject | [PATCH] acpi: Fix regression where _PPC is not read at boot even when ignore_ppc=0 |
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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@us.ibm.com> ---
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
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