Re: DMA problem (?) w/2.4.6-xfs and Serverworks OSB4 Chipset

[Alan Cox]

> I am now running 2.4.9-0.18 kernel as found at Redhat's Rawhide
> which includes Alan's latest diagnostic patches, and am getting
> the message like this:
> 
> end_request: I/O error, dev 16:01 (hdc), sector 2487128
> Curious - OSB4 thinks the DMA is still running.
> OSB4 wait exit.
> hdc: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> hdc: dma_intr: error=0x40 { UncorrectableError }, LBAsect=2487198,
> sector=2487128
> 
> with the "Curious..." patch being the new diagnostics added by Alan.
> All the various failure modes which we see include this error
> message now.
> 
> What does this imply...is there any hope for a fix?

At the moment nope. Probably we should simply default to MWDMA not UDMA
on the OSB4.