Re: old ISA DMA bug in 2.6.12?

[Robert Hancock <hancockr@shaw.ca>]

Bob Tracy wrote:
> I was enjoying yet another session of beating my head against the wall
> trying to do useful things with old hardware :-), and managed to cause a
> kernel panic by simply trying to mount a cdrom in the context of a DSL-N
> installation.
> 
> The SCSI host adapter is an Adaptec AHA-1542B, and when I try to mount a
> cdrom, I manage to run afoul of the BAD_DMA() check in aha1542.c: the
> buffer returned is not in the lower 16 MB of memory.
> 
> The same 2.6.12 kernel + hardware combination works fine as long as I
> confine my I/O to the hard disk that's also attached to the AHA-1542B.

Looks like the aha1542 driver doesn't set the DMA mask, so the kernel 
will default to thinking it can do 32-bit DMA when it should be 24-bit.

-- 
Robert Hancock      Saskatoon, SK, Canada
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