dbffa47161
Current timer_pm.c reads I/O port triple times, in order to avoid the bug of chipset. But I/O port is slow. 2.6.16 (pmtmr) Simple gettimeofday: 3.6532 microseconds 2.6.16+patch (pmtmr) Simple gettimeofday: 1.4582 microseconds [if chip is buggy, probably it will be 7us or more in 4.2% of probability.] This patch adds blacklist of buggy chip, and if chip is not buggy, this uses fast normal version instead of slow workaround version. If chip is buggy, warnings "pmtmr is slow". But sounds like there is gray zone. I found the PIIX4 errata, but I couldn't find the ICH4 errata. But some motherboard seems to have problem. So, if we found a ICH4, generate warnings, and use a workaround version. If user's ICH4 is good, the user can specify the "pmtmr_good" boot parameter to use fast version. Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> |
||
|---|---|---|
| .. | ||
| common.c | ||
| Makefile | ||
| timer_cyclone.c | ||
| timer_hpet.c | ||
| timer_none.c | ||
| timer_pit.c | ||
| timer_pm.c | ||
| timer_tsc.c | ||
| timer.c | ||