[S390] Fix enabled udelay for short delays.
commit78d81f2f844b739b377817cfd279fb6067e191a7
authorChristian Borntraeger <borntraeger@de.ibm.com>
Tue, 6 Oct 2009 08:34:04 +0000 (6 10:34 +0200)
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>
Tue, 6 Oct 2009 08:35:08 +0000 (6 10:35 +0200)
treef252e003e3ead8079a35167eea19f54bc4047964
parent102e835d5152e4299c1d150d6481b9bd47095998
[S390] Fix enabled udelay for short delays.

When udelay() gets called with a delay that would expire before the
next clock event it reprograms the clock comparator.
When the interrupt happens the clock comparator won't be resetted
therefore the interrupt condition doesn't get cleared.
The result is an endless timer interrupt loop until the next clock
event would expire (stored in lowcore).
So udelay() usually would wait much longer for small delays than it
should.

Fix this by disabling the local tick which makes sure that the clock
comparator will be resetted when a timer interrupt happens.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/lib/delay.c