Messages in this thread Patch in this message | | | Date | Fri, 06 Jun 2008 18:02:50 -0700 | From | Chris Wright <> | Subject | [patch 35/50] CPUFREQ: Make acpi-cpufreq more robust against BIOS freq changes behind our back. |
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-stable review patch. If anyone has any objections, please let us know. ---------------------
From: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
upstream commit: e56a727b023d40d1adf660168883f30f2e6abe0a
We checked the hardware freq with OS cached freq value in get_cur_freqon_cpu().
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com> Cc: Thomas Renninger <trenn@suse.de> Cc: "Anthony L. Awtrey" <tony@awtrey.com> [chrisw: backport to 2.6.25.4] Signed-off-by: Chris Wright <chrisw@sous-sol.org> --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -339,6 +339,7 @@ static unsigned int get_cur_freq_on_cpu( { struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu); unsigned int freq; + unsigned int cached_freq; dprintk("get_cur_freq_on_cpu (%d)\n", cpu); @@ -347,7 +348,16 @@ static unsigned int get_cur_freq_on_cpu( return 0; } + cached_freq = data->freq_table[data->acpi_data->state].frequency; freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data); + if (freq != cached_freq) { + /* + * The dreaded BIOS frequency change behind our back. + * Force set the frequency on next target call. + */ + data->resume = 1; + } + dprintk("cur freq = %u\n", freq); return freq; --
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