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[CPUFREQ] powernow-k8: read P-state from HW

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By definition, "cpuinfo_cur_freq" should report the value from HW. So, don't
depend on the cached value. Instead read P-state directly from HW, while
taking into account the erratum 311 workaround for Fam 11h processors.

Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Cc: Thomas Renninger <trenn@suse.de>

Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Reviewed-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Langsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Naga Chumbalkar 2009-06-11 15:26:48 +00:00 committed by Dave Jones
parent b394f1dfc0
commit 532cfee6ba
1 changed files with 10 additions and 13 deletions
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23
arch/x86/kernel/cpu/cpufreq/powernow-k8.c
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@ -118,20 +118,17 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
u32 i = 0;
if (cpu_family == CPU_HW_PSTATE) {
if (data->currpstate == HW_PSTATE_INVALID) {
/* read (initial) hw pstate if not yet set */
rdmsr(MSR_PSTATE_STATUS, lo, hi);
i = lo & HW_PSTATE_MASK;
rdmsr(MSR_PSTATE_STATUS, lo, hi);
i = lo & HW_PSTATE_MASK;
data->currpstate = i;
/*
* a workaround for family 11h erratum 311 might cause
* an "out-of-range Pstate if the core is in Pstate-0
*/
if ((boot_cpu_data.x86 == 0x11) && (i >= data->numps))
data->currpstate = HW_PSTATE_0;
/*
* a workaround for family 11h erratum 311 might cause
* an "out-of-range Pstate if the core is in Pstate-0
*/
if (i >= data->numps)
data->currpstate = HW_PSTATE_0;
else
data->currpstate = i;
}
return 0;
}
do {