fix jiffy calculations in calibrate_delay_direct to handle overflow

Fixes a hang when booting as dom0 under Xen, when jiffies can be
quite large by the time the kernel init gets this far.

Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>
[jbeulich@novell.com: !time_after() -> time_before_eq() as suggested by Jiri Slaby]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tim Deegan 2011-02-10 08:50:41 +00:00 committed by Linus Torvalds
parent 6148a47ac3
commit 70a062286b
1 changed files with 3 additions and 3 deletions

View File

@ -66,7 +66,7 @@ static unsigned long __cpuinit calibrate_delay_direct(void)
pre_start = 0;
read_current_timer(&start);
start_jiffies = jiffies;
while (jiffies <= (start_jiffies + 1)) {
while (time_before_eq(jiffies, start_jiffies + 1)) {
pre_start = start;
read_current_timer(&start);
}
@ -74,8 +74,8 @@ static unsigned long __cpuinit calibrate_delay_direct(void)
pre_end = 0;
end = post_start;
while (jiffies <=
(start_jiffies + 1 + DELAY_CALIBRATION_TICKS)) {
while (time_before_eq(jiffies, start_jiffies + 1 +
DELAY_CALIBRATION_TICKS)) {
pre_end = end;
read_current_timer(&end);
}