[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 <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>

1 files 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 {