DMA memory

Nathan Glasser neg at
Thu Mar 31 05:47:11 EST 2005


Thanks for your suggestions. Unfortunately, my access to the system
has been time-limited, and is coming to an end.

>You can avoid crashes by editing "arch/ppc64/kernel/eeh.c" and
>commenting out the call to eeh_panic().   That might help you with your
>debug efforts.

I'm not sure if it would have been worth trying to rebuild the kernel
for this, but in any case, there's no time now.

>I am afraid that you'll be reduced to staring at PCI bus analyzer traces,
>which is how many of these bugs are found ... :(

This sort of hardware assistance was not available to me, and again
time has run out for me.

>Assuming that you have full access to the device you're coding for, your best
>bet is to add debug code to its firmware, and have it tell you where it plans
>to DMA to; compare that to where you thought it would be going.

While I am very familiar with the device, I don't have control over its
operation in that way. While I could theoretically get someone to do
that, it would be a great deal of trouble, and again time has run out.

Unless someone comes up with a magic formula for me (:-)) I won't be
able to make use of these ideas.


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