diff options
Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index b70344bf6600..13819bfa8dde 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -320,6 +320,9 @@ int lapic_get_maxlvt(void) #define APIC_DIVISOR 16 #define TSC_DIVISOR 8 +/* i82489DX specific */ +#define I82489DX_BASE_DIVIDER (((0x2) << 18)) + /* * This function sets up the local APIC timer, with a timeout of * 'clocks' APIC bus clock. During calibration we actually call @@ -340,8 +343,14 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen) else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE; + /* + * The i82489DX APIC uses bit 18 and 19 for the base divider. This + * overlaps with bit 18 on integrated APICs, but is not documented + * in the SDM. No problem though. i82489DX equipped systems do not + * have TSC deadline timer. + */ if (!lapic_is_integrated()) - lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV); + lvtt_value |= I82489DX_BASE_DIVIDER; if (!irqen) lvtt_value |= APIC_LVT_MASKED; |