On Fri, 1 May 2009 13:37:28 +0100 Russell King <rmk+lkml@xxxxxxxxxxxxxxxx> wrote: > On Fri, May 01, 2009 at 02:25:14PM +0200, Michal Simek wrote: > > Arnd Bergmann wrote: > > > On Friday 01 May 2009, Michal Simek wrote: > > >>> +/* > > >>> + * CLOCK_TICK_RATE is highly PC-specific and should not > > >>> + * be used in portable code. 1193182 is the value for the > > >>> + * original i8253 PIC. > > >>> + */ > > >>> +#ifndef CLOCK_TICK_RATE > > >>> +#define CLOCK_TICK_RATE 1193182 > > >>> +#endif > > >> > > >> Why is this in generic code? > > > > > > CLOCK_TICK_RATE is only used in a few places: Joining in late but its not at all highly PC specific. The same frequency is used for a whole pile of setups (Alpha etc). It's not well named but there are good sound reasons the PC chose 1193182 and while those reasons have long lapsed its a good frequency for other reasons nowdays. The clock isn't for the PIC either - its for the PIT (although its used to clock various other things). We actually have a define of PIT_TICK_RATE internal to the x86 port for those x86 cases that can use it. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
