Re: Disabling data cache

On Tue, Apr 01, 2003 at 05:34:34PM -0800, kas turi wrote:

Hi
  We have a custom made board and we are running 8250
processor. We are using DMA to transmit and receive
data between peripheral and memory. The data is
getting corrupted while transmitting and receiving. We
are suspecting it might be due to data cache being
enabled. So I disabled data cache in the routine
enable_cache in the file arch/ppc/kernel/head.S. I
rebuilt the kernel and when I run on my board it hangs
after printing "Now booting the kernel". I would like
to know why the kernel is not booting up. I have
enclosed the console output:

Sure, you are hitting a number of places in early init
where the kernel uses dcbz.  You need to "fix" those areas
and hack the BAT setting to cache inhibit the DBATs that
map lowmem.  If you search the list archives, I recall an
old email describing what somebody did in detail to run
with dcache disabled on a classic PPC core.

Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

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