Messages in this thread Patch in this message | | | Date | Wed, 9 Jul 2008 23:02:37 +0400 | From | Cyrill Gorcunov <> | Subject | [PATCH -tip] x86: apic LVTT - use APIC_DIVISOR on 64bit mode |
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We use APIC_TDR_DIV_16 while setting APIC_TDCR (divisor) it happened this moment is hidden from __setup_APIC_LVTT caller. So we better increment caller 'clocks' value to not change current behaviour and use APIC_DIVISOR (as already done in 32bit version).
The main benefit - unified procedure code for 32/64bit modes.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> CC: "Maciej W. Rozycki" <macro@linux-mips.org> ---
Please review carefully. Any comments are welcome. I'm _not_ 100% sure if this patch is safe.
Index: linux-2.6.git/arch/x86/kernel/apic_64.c =================================================================== --- linux-2.6.git.orig/arch/x86/kernel/apic_64.c 2008-07-08 22:52:24.000000000 +0400 +++ linux-2.6.git/arch/x86/kernel/apic_64.c 2008-07-08 23:00:24.000000000 +0400 @@ -165,6 +165,9 @@ int lapic_get_maxlvt(void) return maxlvt; } +/* Clock divisor is set to 16 */ +#define APIC_DIVISOR 16 + /* * This function sets up the local APIC timer, with a timeout of * 'clocks' APIC bus clock. During calibration we actually call @@ -197,7 +200,7 @@ static void __setup_APIC_LVTT(unsigned i | APIC_TDR_DIV_16); if (!oneshot) - apic_write(APIC_TMICT, clocks); + apic_write(APIC_TMICT, clocks/APIC_DIVISOR); } /* @@ -329,7 +332,7 @@ static void __init calibrate_APIC_clock( * * No interrupt enable ! */ - __setup_APIC_LVTT(250000000, 0, 0); + __setup_APIC_LVTT(4000000000, 0, 0); apic_start = apic_read(APIC_TMCCT); #ifdef CONFIG_X86_PM_TIMER
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