Re: mlord ide patch 2.1.94

mlord (mlord@pobox.com)
Mon, 13 Apr 1998 18:14:32 -0400


Simone Fabris wrote:
>
> > > PCI_IDE: unknown IDE controller on PCI bus 00 device 58, VID=10b9, DID=5229
> > > PCI_IDE: not 100% native mode: will probe irqs later
> > > PCI_IDE: simplex device: DMA disabled
> > > ide0: PCI_IDE Bus-Master DMA disabled (BIOS)
> > > PCI_IDE: simplex device: DMA disabled
> > > ide1: PCI_IDE Bus-Master DMA disabled (BIOS)
> > > hda: WDC AC36400L, ATA DISK drive

The chipset claims to be "simplex", meaning that DMA can only be used
on one interface at a time. This is a broken design, and our IDE driver
does not bother even trying to manage DMA on such setups.

I might add something in 2.3.xx for it.

> Anyway, DMA is not the only strange thing with this motherboard under linux: I can't neither set any PIO mode!! Does not work neither ``hdparm -p<anything> /dev/hda'' or ``echo "pio_mode:3">/proc/ide/hda/settings'' (linux-2.1.95).

Linux does NOT include support for setting chipset modes for PCI
IDE interfaces. Instead, you can write your own user-mode bit-twiddler
that uses the /proc/ide/*/config interface to *safely* update the
chipset settings on the fly.

-- 
mlord@pobox.com
The Linux IDE guy

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