[CPUFREQ] speedstep-centrino: skip extract_clock logic for acpi based centrino

speedstep_centrino.c:extract_clock() assumes the bus speed of 100MHz, which is
not true with latest laptops. Due to this assumption and due to the encoded
frequency check during initialization, speedstep-centrino driver fails even
on systems that has proper ACPI information to do the P-state transition.

The change below moves the centrino-speedstep detection to be used only
when table based P-state transition is done. For ACPI based P-state
transition, we skip the centrino_cpu identification, and as a result we
don't use the bus speed assumption in extract_clock. This change makes
speedstep-centrino work on Pentium-M based systems, which have more than 100MHz
bus speed.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>

diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
index 327a55d4d1c67b878f885f08cf353d06d816a057..95e15b7fce17f1a1beb65a0e553551ff19aa60a0 100644 (file)
--- a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -498,13 +498,6 @@ static int centrino_cpu_init(struct cpufreq_policy *policy)
        if (cpu->x86_vendor != X86_VENDOR_INTEL || !cpu_has(cpu, X86_FEATURE_EST))
                return -ENODEV;
 
-       for (i = 0; i < N_IDS; i++)
-               if (centrino_verify_cpu_id(cpu, &cpu_ids[i]))
-                       break;
-
-       if (i != N_IDS)
-               centrino_cpu[policy->cpu] = &cpu_ids[i];
-
        if (is_const_loops_cpu(policy->cpu)) {
                centrino_driver.flags |= CPUFREQ_CONST_LOOPS;
        }
@@ -513,6 +506,13 @@ static int centrino_cpu_init(struct cpufreq_policy *policy)
                if (policy->cpu != 0)
                        return -ENODEV;
 
+               for (i = 0; i < N_IDS; i++)
+                       if (centrino_verify_cpu_id(cpu, &cpu_ids[i]))
+                               break;
+
+               if (i != N_IDS)
+                       centrino_cpu[policy->cpu] = &cpu_ids[i];
+
                if (!centrino_cpu[policy->cpu]) {
                        dprintk(KERN_INFO PFX "found unsupported CPU with "
                        "Enhanced SpeedStep: send /proc/cpuinfo to "