Re: linux-2.5.6 scsi DMA mapping and compilation fixes (not yet working)

[Alan Cox]

> I believe changes to NCR53c80 were recently reverted back because
> these "fixes" lead to massive data corruption.  It is preferable
> that the driver remains unbuildable, and therefore doesn't cause
> data corruption than to be buildable and case data corruption.

Someone "fixed" the 2.5 one by just frobbing randomly with the
io_request_lock without noticing its not always used per queue in the driver
(study the host list code - and dont think you can just clean that up by
 using SHIRQ - that wont help on some non x86 stuff). I fed Dave Jones
the 2.4 stuff where the locking is fixed (tho using io_request_lock) and
actually works SMP.

Dave then I suspect fed it to Linus