Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq

[pandora-kernel.git] / arch / x86 / kernel / cpu / cpufreq / longhaul.c

diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/x86/kernel/cpu/cpufreq/longhaul.c
similarity index 91%
rename from arch/i386/kernel/cpu/cpufreq/longhaul.c
rename to arch/x86/kernel/cpu/cpufreq/longhaul.c
index a2fbfd9..5045f5d 100644 (file)
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/x86/kernel/cpu/cpufreq/longhaul.c
@@ -76,6 +76,7 @@ static unsigned int longhaul_index;
 /* Module parameters */
 static int scale_voltage;
 static int disable_acpi_c3;
+static int revid_errata;
 
 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "longhaul", msg)
 
@@ -168,7 +169,10 @@ static void do_powersaver(int cx_address, unsigned int clock_ratio_index,
 
        rdmsrl(MSR_VIA_LONGHAUL, longhaul.val);
        /* Setup new frequency */
-       longhaul.bits.RevisionKey = longhaul.bits.RevisionID;
+       if (!revid_errata)
+               longhaul.bits.RevisionKey = longhaul.bits.RevisionID;
+       else
+               longhaul.bits.RevisionKey = 0;
        longhaul.bits.SoftBusRatio = clock_ratio_index & 0xf;
        longhaul.bits.SoftBusRatio4 = (clock_ratio_index & 0x10) >> 4;
        /* Setup new voltage */
@@ -272,7 +276,7 @@ static void longhaul_setstate(unsigned int table_index)
 
        dprintk ("Setting to FSB:%dMHz Mult:%d.%dx (%s)\n",
                        fsb, mult/10, mult%10, print_speed(speed/1000));
-
+retry_loop:
        preempt_disable();
        local_irq_save(flags);
 
@@ -344,6 +348,47 @@ static void longhaul_setstate(unsigned int table_index)
        preempt_enable();
 
        freqs.new = calc_speed(longhaul_get_cpu_mult());
+       /* Check if requested frequency is set. */
+       if (unlikely(freqs.new != speed)) {
+               printk(KERN_INFO PFX "Failed to set requested frequency!\n");
+               /* Revision ID = 1 but processor is expecting revision key
+                * equal to 0. Jumpers at the bottom of processor will change
+                * multiplier and FSB, but will not change bits in Longhaul
+                * MSR nor enable voltage scaling. */
+               if (!revid_errata) {
+                       printk(KERN_INFO PFX "Enabling \"Ignore Revision ID\" "
+                                               "option.\n");
+                       revid_errata = 1;
+                       msleep(200);
+                       goto retry_loop;
+               }
+               /* Why ACPI C3 sometimes doesn't work is a mystery for me.
+                * But it does happen. Processor is entering ACPI C3 state,
+                * but it doesn't change frequency. I tried poking various
+                * bits in northbridge registers, but without success. */
+               if (longhaul_flags & USE_ACPI_C3) {
+                       printk(KERN_INFO PFX "Disabling ACPI C3 support.\n");
+                       longhaul_flags &= ~USE_ACPI_C3;
+                       if (revid_errata) {
+                               printk(KERN_INFO PFX "Disabling \"Ignore "
+                                               "Revision ID\" option.\n");
+                               revid_errata = 0;
+                       }
+                       msleep(200);
+                       goto retry_loop;
+               }
+               /* This shouldn't happen. Longhaul ver. 2 was reported not
+                * working on processors without voltage scaling, but with
+                * RevID = 1. RevID errata will make things right. Just
+                * to be 100% sure. */
+               if (longhaul_version == TYPE_LONGHAUL_V2) {
+                       printk(KERN_INFO PFX "Switching to Longhaul ver. 1\n");
+                       longhaul_version = TYPE_LONGHAUL_V1;
+                       msleep(200);
+                       goto retry_loop;
+               }
+       }
+       /* Report true CPU frequency */
        cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 
        if (!bm_timeout)
@@ -959,11 +1004,20 @@ static void __exit longhaul_exit(void)
        kfree(longhaul_table);
 }
 
+/* Even if BIOS is exporting ACPI C3 state, and it is used
+ * with success when CPU is idle, this state doesn't
+ * trigger frequency transition in some cases. */
 module_param (disable_acpi_c3, int, 0644);
 MODULE_PARM_DESC(disable_acpi_c3, "Don't use ACPI C3 support");
-
+/* Change CPU voltage with frequency. Very usefull to save
+ * power, but most VIA C3 processors aren't supporting it. */
 module_param (scale_voltage, int, 0644);
 MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor");
+/* Force revision key to 0 for processors which doesn't
+ * support voltage scaling, but are introducing itself as
+ * such. */
+module_param(revid_errata, int, 0644);
+MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID");
 
 MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>");
 MODULE_DESCRIPTION ("Longhaul driver for VIA Cyrix processors.");