DMA memory

Jake Moilanen moilanen at
Tue Mar 29 03:53:28 EST 2005

> RTAS: 2 --------- RTAS event begin
> RTAS 0: 00000000 00000000
> RTAS: 2 --------- RTAS event end
> Kernel panic: EEH: MMIO failure (2) on device:pci12e4,1000 /pci at 400000000111/pci at 2,6/pci12e4,1000 at 1
> It was suggested to me that the DMA was to a bad address, and that this
> caused the device to be isolated. I didn't know the system could do that,
> but it makes sense to me.

That's what it looks like.  pSeries does isolation when a bad DMA is
attempted through EEH.

> Assuming you trust that these dma handle values are properly being sent to the
> device, does anyone have any suggestions for what I'm doing wrong? Is there
> some further translation I need to do of the dma handle before passing it to
> the device? Other drivers I looked at didn't seem to.

>From what I can see on your setup, it looks good.  Here's a couple
things to check:

- Passing the correct endiness on your DMA handle to the adapter. 

- If you had a real old version of firmware on the 630, there was a
problem w/ PCI-2-PCI bridges that we hit on a 2.4 kernel (I can't
remember the details).  Turn on Linux Compatibility Mode from the
Service Processor Menus.  Here's a link:


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