tree 79e56b4a1abef756e94a26067aa2d5922a364998
parent b0ff153cd6228b2502e1c3ce5e226b82ae4e0679
author Stefan Roese <sr@denx.de> 1263248934 +0000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> 1263522375 +1100

powerpc: Fix decrementer setup on 1GHz boards

We noticed that recent kernels didn't boot on our 1GHz Canyonlands 460EX
boards anymore. As it seems, patch 8d165db1 [powerpc: Improve
decrementer accuracy] introduced this problem. The routine div_sc()
overflows with shift = 32 resulting in this incorrect setup:

time_init: decrementer frequency = 1000.000012 MHz
time_init: processor frequency   = 1000.000012 MHz
clocksource: timebase mult[400000] shift[22] registered
clockevent: decrementer mult[33] shift[32] cpu[0]

This patch now introduces a local div_dc64() version of this function
so that this overflow doesn't happen anymore.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Detlev Zundel <dzu@denx.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>