BUG in drivers/dma/ioat/dma_v2.c:314

From: Chris Li
Date: Mon Jun 28 2010 - 19:50:16 EST

Hi Dan,

My Mac Pro hit this BUG every time it try to load module ioatdma.

This was first discover in FC 12 & 13 kernel. See redhat bug 605845.
https://bugzilla.redhat.com/show_bug.cgi?id=605845. I attach a picture
of the kernel panic on the bug.

The current git tree has it as well. The bug line number change a
little bit though.

/* when halted due to errors check for channel
* programming errors before advancing the completion state
if (is_ioat_halted(status)) {
u32 chanerr;

chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
dev_err(to_dev(chan), "%s: Channel halted (%x)\n",
__func__, chanerr);
BUG_ON(is_ioat_bug(chanerr)); <---------------------------------

The machine is a Mac Pro. The bug is reproducible 100%. Black list the
ioatdma module and the kernel boot just fine.

Any suggestion? I am not afraid to try out patches.


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