Messages in this thread | | | Date | Wed, 18 Jun 2003 01:31:14 +0200 | From | Vojtech Pavlik <> | Subject | Re: [patch] input: Fix CLOCK_TICK_RATE usage ... [8/13] |
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On Tue, Jun 17, 2003 at 04:24:04PM -0700, David Mosberger wrote: > >>>>> On Wed, 18 Jun 2003 01:14:11 +0200, Vojtech Pavlik <vojtech@suse.cz> said: > > >> Sounds much better to me. Wouldn't something along the lines of > >> this make the most sense: > > >> #ifdef __ARCH_PIT_FREQ # define PIT_FREQ __ARCH_PIT_FREQ #else # > >> define PIT_FREQ 1193182 #endif > > >> After all, it seems like the vast majority of legacy-compatible > >> hardware _do_ use the standard frequency. > > Vojtech> Now, if this was in some nice include file, along with the > Vojtech> definition of the i8253 PIT spinlock, that'd be > Vojtech> great. Because not just the beeper driver uses the PIT, > Vojtech> also some joystick code uses it if it is available. > > ftape, too. The LATCH() macro should also be moved to such a header > file, I think. How about just creating asm/pit.h? Only platforms > that need to (potentially) support legacy hardware would need to > define it. E.g., on ia64, we could do: > > #ifndef _ASM_IA64_PIT_H > #define _ASM_IA64_PIT_H > > #include <linux/config.h> > > #ifdef CONFIG_LEGACY_HW > # define PIT_FREQ 1193182 > # define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) > #endif > > #endif /* _ASM_IA64_PIT_H */ > > This way, machines that support legacy hardware can define > CONFIG_LEGACY_HW and on others, the macro can be left undefined, so > that any attempt to compile drivers requiring legacy hw would fail to > compile upfront (much better than accessing random ports!).
Yes, that looks very good indeed. Riley?
-- Vojtech Pavlik SuSE Labs, SuSE CR - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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