From 455c0d71d46e86b0b7ff2c9dcfc19bc162302ee9 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 18 Feb 2010 10:28:20 -0800 Subject: [PATCH] ACPI: Fix regression where _PPC is not read at boot even when ignore_ppc=0 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 Signed-off-by: Len Brown --- drivers/acpi/processor_perflib.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 2cabadcc4d8c..a959f6a07508 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -413,7 +413,11 @@ 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_get_platform_limit(pr); + + return result; /* * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that -- 2.39.5