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-rw-r--r--Documentation/cpu-freq/user-guide.txt12
-rw-r--r--arch/x86/kernel/cpu/cpufreq/powernow-k8.c18
-rw-r--r--arch/x86/kernel/cpu/cpufreq/powernow-k8.h17
3 files changed, 43 insertions, 4 deletions
diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
index 6c442d8426b5..4f3f3840320e 100644
--- a/Documentation/cpu-freq/user-guide.txt
+++ b/Documentation/cpu-freq/user-guide.txt
@@ -23,6 +23,7 @@ Contents:
1.3 sparc64
1.4 ppc
1.5 SuperH
+1.6 Blackfin
2. "Policy" / "Governor"?
2.1 Policy
@@ -97,6 +98,17 @@ The following SuperH processors are supported by cpufreq:
SH-3
SH-4
+1.6 Blackfin
+------------
+
+The following Blackfin processors are supported by cpufreq:
+
+BF522, BF523, BF524, BF525, BF526, BF527, Rev 0.1 or higher
+BF531, BF532, BF533, Rev 0.3 or higher
+BF534, BF536, BF537, Rev 0.2 or higher
+BF561, Rev 0.3 or higher
+BF542, BF544, BF547, BF548, BF549, Rev 0.1 or higher
+
2. "Policy" / "Governor" ?
==========================
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index d3dcd58b87cd..7f05f44b97e9 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -115,9 +115,20 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
u32 i = 0;
if (cpu_family == CPU_HW_PSTATE) {
- rdmsr(MSR_PSTATE_STATUS, lo, hi);
- i = lo & HW_PSTATE_MASK;
- data->currpstate = i;
+ 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;
+ }
return 0;
}
do {
@@ -1121,6 +1132,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
}
data->cpu = pol->cpu;
+ data->currpstate = HW_PSTATE_INVALID;
if (powernow_k8_cpu_init_acpi(data)) {
/*
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
index ab48cfed4d96..65cfb5d7f77f 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -5,6 +5,19 @@
* http://www.gnu.org/licenses/gpl.html
*/
+
+enum pstate {
+ HW_PSTATE_INVALID = 0xff,
+ HW_PSTATE_0 = 0,
+ HW_PSTATE_1 = 1,
+ HW_PSTATE_2 = 2,
+ HW_PSTATE_3 = 3,
+ HW_PSTATE_4 = 4,
+ HW_PSTATE_5 = 5,
+ HW_PSTATE_6 = 6,
+ HW_PSTATE_7 = 7,
+};
+
struct powernow_k8_data {
unsigned int cpu;
@@ -23,7 +36,9 @@ struct powernow_k8_data {
u32 exttype; /* extended interface = 1 */
/* keep track of the current fid / vid or pstate */
- u32 currvid, currfid, currpstate;
+ u32 currvid;
+ u32 currfid;
+ enum pstate currpstate;
/* the powernow_table includes all frequency and vid/fid pairings:
* fid are the lower 8 bits of the index, vid are the upper 8 bits.