Re: 3.14.3-rt5: at91: Crash early at boot

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

Hi Maxime,

On 16/03/2015 at 19:19:00 +0100, Maxime Ripard wrote :
> Hi,
> 
> On Tue, Feb 17, 2015 at 09:38:59AM +0100, Sebastian Andrzej Siewior wrote:
> > * Maxime Ripard | 2014-06-13 16:25:06 [+0200]:
> > 
> > >Preemptible hierarchical RCU implementation.
> > >NR_IRQS:16 nr_irqs:16 16
> > >Unable to handle kernel NULL pointer dereference at virtual address 00000000
> > >pgd = c0004000
> > >[00000000] *pgd=00000000
> > >Internal error: Oops: 5 [#1] PREEMPT ARM
> > >Modules linked in:
> > >CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.3-rt4+ #11
> > >task: c05ecb28 ti: c05e2000 task.ti: c05e2000
> > >PC is at wake_up_process+0x8/0x40
> > >LR is at kthread_create_on_node+0xb0/0x178
> > …
> > >Do you know what could be the cause of this, or is this any known issue?
> > 
> > No. This is very early in the boot process. I upgrade the at91's timer
> > patches but have no HW to actually check if this is still working.
> 
> Do you have a link to these patches?
> 
The issue has been solved at emtrion but I think the patches were not
sent yet. The issue is that threading the timer IRQs leads to a crash
because kthreadd is not started yet.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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