Re: 2.4.18: many IDE errors

[Eyal Lebedinsky <eyal@eyal.emu.id.au>]

Andre Hedrick wrote:
> 
> On Sun, 24 Mar 2002, Eyal Lebedinsky wrote:
> 
> > If I understand correctly, the basic answer is that this is not
> > a driver issue, and not a general kernel (irq's etc.) either, but
> > a true hardware problem.
> >
> >
> > Andre Hedrick wrote:
> > >
> > > It is not a case of bad cables but maybe cable routing.
> >
> > I am not clear on what cable routing means. Can you elaborate?
> 
> If you have many cable (note there are random ways to construct, odd/even)
> You can get crosstalk (aka 0x51/0x84 kernel noise).  These messages are
> telling you the hardware checksum between the HOST and DEVICE failed.
> The solution is to retry, and the driver does.

[explanation of rate backoff trimmed]

Yes, I see this happening, and I agree it is a good idea.

> > I know they come up ATA-5. Here are the relevant bootup messages:
> >
> > Uniform Multi-Platform E-IDE driver Revision: 6.31
> > ide: Assuming 33MHz system bus speed for PIO modes; override with
> > idebus=xx
> > VP_IDE: IDE controller on PCI bus 00 dev 39
> > VP_IDE: chipset revision 6
> > VP_IDE: not 100% native mode: will probe irqs later
> > ide: Assuming 33MHz system bus speed for PIO modes; override with
> > idebus=xx
> > VP_IDE: VIA vt82c686b (rev 40) IDE UDMA100 controller on pci00:07.1
> >     ide0: BM-DMA at 0xffa0-0xffa7, BIOS settings: hda:DMA, hdb:pio
> >     ide1: BM-DMA at 0xffa8-0xffaf, BIOS settings: hdc:DMA, hdd:DMA
> 
> First disable unmasking VIA it makes a mess. :-/
> 
> This (CMD649) is a good HOST and Linux can deal nicely.

You mean IRQ unmasking? This is interesting. After bootup I see hda/c
(on VP_IDE, ide0/1) having
	I/O support:	1
	unmasking:	1
but hde/g/i/k (on CMD649, ide2/3/4/5) have:
	I/O support:	0
	unmasking:	0
So VIA unmasking is NOT disabled (I will do so) but why is the CMD649
disabled if you say it is a good chipset?

--
Eyal Lebedinsky (eyal@eyal.emu.id.au) <http://samba.org/eyal/>