Re: !!Warning!! UDMA and Fujitsu HD

Peter T. Breuer (ptb@it.uc3m.es)
Mon, 3 Aug 1998 22:03:36 +0200 (MET DST)

"A month of sundays ago Gadi Oxman wrote:"
>
> On Mon, 3 Aug 1998, Peter T. Breuer wrote:
>
> > Uh .. you are braver than me. I didn't even try once I saw the lockup with
> > -X34. At first I thought it was a compatibility problem with the seagate that
> > I had on the same controller then. Nope.
>
> The lockup probably occured since the chipset was configured to using
> UDMA timing by the BIOS, yet issuing -X34 to the drive sets it to the
> slower DMA mode 2 timing without re-programming the chipset first.

Confirm. Lockup seen on a BX board, which would have been using UDMA,
when I used the default hda config taken from my 3 year old T1 board (A
triton 1, not a TX Pro, as people seem to think) which would not have
had UDMA. Kernels and disks are the same across the two boards. Only
the boards differ.

It looks like a touch (-X34 -d1) with hdparm that served to boost the
performance of an older DMA disk on older boards is disastrous on a
UDMA disk on newer boards. Some of the reports of UDMA unreliability
may be mistaken ... people seeing errors may have to recheck that they
aren't resetting the disk inappropriately using hdparm.

> Gadi

Peter

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html