Tony Lindgren wrote:
> - CONFIG_DEBUG_LL hangs system

For reference see

http://linux.omap.com/pipermail/linux-omap-open-source/2006-October/008025.html

and

http://linux.omap.com/pipermail/linux-omap-open-source/2006-October/008054.html

for an ugly workaround if you really need it. I really have
no clue what is broken here.

> - BUG in omap1_mbox_enable_irq

I think you mean

Unbalanced enable for IRQ 10
BUG: warning at kernel/irq/manage.c:118/enable_irq()

printed in bootmessages.

I spent some minutes for this as well. It is MPU "dsp"
interrupt which is enabled in omap1_mbox_enable_irq() by

enable_irq(mbox->irq);

In kernel/irq/manage.c function enable_irq() checks for
desc->depth and if it is 0 it prints above message. Seems
that desc->depth has to be >= 1.

The comment tells us

*	Undoes the effect of one call to disable_irq().  If this
*	matches the last disable, processing of interrupts on this
*	IRQ line is re-enabled.

so seems that before calling enable_irq() at least one
disable_irq() is needed.

I don't know if patch in attachment is a valid patch or only
a workaround. What do you think?

Best regards

Dirk