Hi,

after Tony updated to -rc6 (thanks!) I tried latest
CONFIG_PREEMPT_RT patch on OSK. For more details see [1].

First, I applied our clocksource patch [2], then preempt rt
patch [3]. This doesn't apply totally cleanly, it fails in
arch/arm/plat-omap/gpio.c which seems to be different in
mainline and our git. Fixing this and converting some OMAP
specific spinlocks to raw_spinlocks (is this correct?) not
in mainline, system boots. Resulting OMAP specific patch in
attachment, apply it on top of [2] & [3].

Result:

- System boots
- Can play MP3 via NFS, however Oops after MP3 finished [4]

Still not perfect, but a starting point :)

Maybe this is interesting for other people as well,

Dirk

[1] rt.wiki.kernel.org

[2]
http://linux.omap.com/pipermail/linux-omap-open-source/2006-November/008370.html

[3]
http://people.redhat.com/mingo/realtime-preempt/patch-2.6.19-rc6-rt3 



[4] Oops after madplay finishes:

kernel BUG at kernel/rtmutex.c:672!
Unable to handle kernel NULL pointer dereference at virtual
address 00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: Oops: 817 [#1]
PC is at __bug+0x44/0x58
LR is at rt_up+0x4c/0x6c