diff options
Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq')
| -rw-r--r-- | arch/i386/kernel/cpu/cpufreq/longhaul.c | 60 |
1 files changed, 57 insertions, 3 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c index ef8f0bc3fc7..f0cce3c2dc3 100644 --- a/arch/i386/kernel/cpu/cpufreq/longhaul.c +++ b/arch/i386/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) @@ -956,11 +1001,20 @@ 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."); |