[alsa-devel] Writing an AT91SAM9260-EK Dumb Codec Driver

[Liam Girdwood]

On Mon, 2007-06-18 at 18:15 +0100, Liam Girdwood wrote:
> On Mon, 2007-06-18 at 12:07 -0500, Paul Kavan wrote:
> > I now have the linux-2.6.22-rc1 kernel booting correctly without the
> > aSoC driver activated in .config. However, when I rebuild with the
> > aSoC and then boot, I get the following crash:
> > 
> > .snip.
> > Advanced Linux Sound Architecture Driver Version 1.0.14rc4 (Wed May 09
> > 09:51:39 2007 UTC).
> > ASoC version 0.13.0 
> > Unable to handle kernel NULL pointer dereference at virtual address
> > 00000001
> > pgd = c0004000
> > [00000001] *pgd=00000000
> > Internal error: Oops: 801 [#1]
> > Modules linked in:
> > CPU: 0
> > PC is at grh_ek_w6811_init+0x4c/0x11c
> > LR is at __arm_ioremap_pfn+0x2cc/0x2ec
> 
> You have a NULL pointer dereference in grh_ek_w6811_init(), most likely
> to be ssc as the dai private data wont be set yet. i.e.
> 
> struct at91_ssc_periph *ssc = grh_ek_w6811_dai.cpu_dai->private_data;

Forgot to add the deref itself :-

ssc->base = ioremap(AT91SAM9260_BASE_SSC, SZ_16K);

ssc is probably NULL.

Liam