Re: AMD viper chipset and UDMA100

[Vojtech Pavlik]

On Thu, Sep 27, 2001 at 03:16:18PM -0700, Dan Hollis wrote:

> On Thu, 27 Sep 2001, Vojtech Pavlik wrote:
> > On Thu, Sep 27, 2001 at 02:26:50PM -0700, Sean Swallow wrote:
> > > I just got a tyan tiger w/ the AMD Viper chipset on it. For some reason
> > > Linux will only set the onboard (AMD viper) chains to UDMA33.
> > > I'm using linux 2.4.9, and I have also tried 2.4.10. Is there a limitation
> > > to the AMD Viper driver?
> > > PS. The cables (2) are BRAND new ata100 cables.
> > The Viper can do UDMA66 max. At least it's doing it for me quite well.
> 
> If he's got the Tyan Tiger i'm thinking of, it's the Tyan S2460 with
> AMD766 southbridge. Tyan says it will do U100:
> http://www.tyan.com/products/html/tigermp.html

This southbridge is called Viper Plus as far as I know. In the past,
I've written a driver for this, but it didn't make it into the kernel,
because Andre also had his version.

> AMD does too:
> http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_873,00.html
> 
> And I've got the same problem with my S2460:
> 
> Uniform Multi-Platform E-IDE driver Revision: 6.31
> ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
> AMD7411: IDE controller on PCI bus 00 dev 39
> AMD7411: chipset revision 1
> AMD7411: not 100% native mode: will probe irqs later
> AMD7411: disabling single-word DMA support (revision < C4)
>     ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:pio
>     ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:DMA, hdd:pio
> hda: 20010816 sectors (10246 MB) w/2048KiB Cache, CHS=1245/255/63, UDMA(33)
> hdc: 160086528 sectors (81964 MB) w/2048KiB Cache, CHS=158816/16/63, UDMA(33)
> 
> But these drives will do U66/U100:
> 
> And yes, I *DO* have the proper cables. These same drives connected to a
> Promise 20267 or a VIA KT133 with the same cables will do U66/U100
> perfectly.

Perhaps I could dig up my code and you can give it a test. Would you be
interested?

-- 
Vojtech Pavlik
SuSE Labs