[PATCH] OMAP2+: clocksource: fix crash on boot when !CONFIG_OMAP_32K_TIMER

Tony Lindgren tony at atomide.com
Thu Feb 24 15:21:57 EST 2011


* Paul Walmsley <paul at pwsan.com> [110222 18:58]:
> 
> OMAP2+ kernels built without CONFIG_OMAP_32K_TIMER crash on boot after the
> 2.6.38 sched_clock changes:
> 
> [    0.000000] OMAP clockevent source: GPTIMER1 at 13000000 Hz
> [    0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000
> [    0.000000] pgd = c0004000
> [    0.000000] [00000000] *pgd=00000000
> [    0.000000] Internal error: Oops: 80000005 [#1] SMP
> [    0.000000] last sysfs file:
> [    0.000000] Modules linked in:
> [    0.000000] CPU: 0    Not tainted  (2.6.38-rc5-00057-g04aa67d #152)
> [    0.000000] PC is at 0x0
> [    0.000000] LR is at sched_clock_poll+0x2c/0x3c
> 
> Without CONFIG_OMAP_32K_TIMER, the kernel has an clockevent and
> clocksource resolution about three orders of magnitude higher than
> with CONFIG_OMAP_32K_TIMER set.  The tradeoff is that the lowest
> power consumption states are not available.
> 
> Fix by calling init_sched_clock() from the GPTIMER clocksource init code.

I'll queue this as a fix as it's a regression.

Tony



More information about the linux-arm-kernel mailing list