Oops accessing BCSR on 8272ADS

Oops accessing BCSR on 8272ADS

[Alex Zeffertt]

Hi list,

I've just downloaded linux-2.4.31 from kernel.org and compiled it for
the mpc8272ads board.

When I boot the kernel it oopses in fcc_enet.c:init_fcc_startup() at
the point where it tries to write to the BCSR.

Does anybody know why writing to the BCSR should cause a machine
check?

TIA,

Alex

Re: Oops accessing BCSR on 8272ADS

[Vitaly Bordug]

Alex Zeffertt wrote:
> Hi list,
> 
> I've just downloaded linux-2.4.31 from kernel.org and compiled it for
> the mpc8272ads board.
> 
> When I boot the kernel it oopses in fcc_enet.c:init_fcc_startup() at
> the point where it tries to write to the BCSR.
> 
> Does anybody know why writing to the BCSR should cause a machine
> check?
> 
I guess I was not ioremapped/io_block_mapped properly.
Take a look into arch/ppc/kernel/m8260_setup.c m8260_map_io() function.
Anyway BCSR is better to be ioremapped in the place it is required.
> TIA,
> 
> Alex
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> 
> 


-- 
Sincerely,
Vitaly

Re: Oops accessing BCSR on 8272ADS

[Alex Zeffertt]

> > 
> It depends on which u-boot you're using and there I'm aware of
> issues when BCSR resides somewhere different... Try 0xF8000000.
> Don't you have btw
> 

Thanks Vitaly.  You were right.  In my u-boot - version 1.1.1 - it was
0xf8000000 not 0xf4500000.  I just modified BCSR_ADDR and that stopped
the oops.

Cheers,

Alex