The desired effect of a DMA timeout should be to throw an I/O error, but 
that doesn't appear to be happening.

Those seeing DMA timeout messages, please test this patch.

Kernel hacker note:  James B recommended that I implement my own 
scsi_done() function, which duplicates the real scsi_done() but omits 
the scsi_delete_timer() call.  This is probably the best long term fix, 
but doing so involves exporting several currently-private bits of SCSI 
mid-layer, which I would rather not do.  Probably best to create a 
__scsi_done() inside the SCSI mid-layer, and call that.

	Jeff, the only user of ->eh_strategy_handler() in any kernel