]> git.baikalelectronics.ru Git - kernel.git/commit
hwmon: applesmc: lighter wait mechanism, drastic improvement
authorHenrik Rydberg <rydberg@euromail.se>
Sun, 19 Oct 2008 03:27:43 +0000 (20:27 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 20 Oct 2008 15:52:35 +0000 (08:52 -0700)
commit9dc8f6458a1f1b9322dee08cf723e9ab731ac9ed
tree160520c76c2dfbe89398b6c53aa8813e212abed3
parentc4f568e03910b1778e39e89ece300c36c27daf6f
hwmon: applesmc: lighter wait mechanism, drastic improvement

The read fail ratio is sensitive to the delay between the first byte
written and the first byte read; apparently the sensors cannot be rushed.
Increasing the minimum wait time, without changing the total wait time,
improves the fail ratio from a 8% chance that any of the sensors fails in
one read, down to 0.4%, on a Macbook Air.  On a Macbook Pro 3,1, the
effect is even more apparent.  By reducing the number of status polls, the
ratio is further improved to below 0.1%.  Finally, increasing the total
wait time brings the fail ratio down to virtually zero.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Tested-by: Bob McElrath <bob@mcelrath.org>
Cc: Nicolas Boichat <nicolas@boichat.ch>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/hwmon/applesmc.c