From 532cfee6ba0a8efcf7c3ce38b9881292d79d516e Mon Sep 17 00:00:00 2001 From: Naga Chumbalkar Date: Thu, 11 Jun 2009 15:26:48 +0000 Subject: [PATCH] [CPUFREQ] powernow-k8: read P-state from HW 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 Cc: Langsdorf, Mark Cc: Thomas Renninger Signed-off-by: Naga Chumbalkar Reviewed-by: Andreas Herrmann Tested-by: Andreas Herrmann Acked-by: Langsdorf, Mark Signed-off-by: Thomas Renninger Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 25 ++++++++++------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index 2709b3c183b4..331021112f2b 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -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; - - /* - * 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; - } + 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; + return 0; } do { -- 2.34.1