diff options
| -rw-r--r-- | arch/x86/include/asm/i8259.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/tsc.c | 18 |
2 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/include/asm/i8259.h b/arch/x86/include/asm/i8259.h index c8376b40e882..5cdcdbd4d892 100644 --- a/arch/x86/include/asm/i8259.h +++ b/arch/x86/include/asm/i8259.h @@ -69,6 +69,11 @@ struct legacy_pic { extern struct legacy_pic *legacy_pic; extern struct legacy_pic null_legacy_pic; +static inline bool has_legacy_pic(void) +{ + return legacy_pic != &null_legacy_pic; +} + static inline int nr_legacy_irqs(void) { return legacy_pic->nr_legacy_irqs; diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index e169e85db434..a2c9dd8bfc6f 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -25,6 +25,7 @@ #include <asm/geode.h> #include <asm/apic.h> #include <asm/intel-family.h> +#include <asm/i8259.h> unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */ EXPORT_SYMBOL(cpu_khz); @@ -363,6 +364,20 @@ static unsigned long pit_calibrate_tsc(u32 latch, unsigned long ms, int loopmin) unsigned long tscmin, tscmax; int pitcnt; + if (!has_legacy_pic()) { + /* + * Relies on tsc_early_delay_calibrate() to have given us semi + * usable udelay(), wait for the same 50ms we would have with + * the PIT loop below. + */ + udelay(10 * USEC_PER_MSEC); + udelay(10 * USEC_PER_MSEC); + udelay(10 * USEC_PER_MSEC); + udelay(10 * USEC_PER_MSEC); + udelay(10 * USEC_PER_MSEC); + return ULONG_MAX; + } + /* Set the Gate high, disable speaker */ outb((inb(0x61) & ~0x02) | 0x01, 0x61); @@ -487,6 +502,9 @@ static unsigned long quick_pit_calibrate(void) u64 tsc, delta; unsigned long d1, d2; + if (!has_legacy_pic()) + return 0; + /* Set the Gate high, disable speaker */ outb((inb(0x61) & ~0x02) | 0x01, 0x61); |