Re: ide.2.4.1-p3.01112001.patch

[Alan Cox]

> I want to see the code to handle the apparent VIA DMA bug. At this point,
> preferably by just disabling DMA on VIA chipsets or something like that
> (if it has only gotten worse since 2.2.x, I'm not interested in seeing any
> experimental patches for it during early 2.4.x).

It hasnt gotten worse, its just its a very specific combination and its a 
well known problem (vendors dont enable auto dma for ide for this reason)
2.2.16 just covers the cases I know about (and slightly overdoes it for now)

> We've already had one major fs corruption due to this, I want that fixed
> _first_.

I've got other reports too. 

The PCI ids I kill autodma on for 2.2 to cover this are:

                /*
                 *      Don't try and tune a VIA 82C586 or 586A
                 */
                if (IDE_PCI_DEVID_EQ(devid, DEVID_VP_IDE))
                {
                        autodma_default = 0;
                        break;
                }
                if (IDE_PCI_DEVID_EQ(devid, DEVID_VP_OLDIDE))
                {
                        autodma_default = 0;
                        break;
                }

PCI_VENDOR_ID_VIA,     PCI_DEVICE_ID_82C586_0
PCI_VENDOR_ID_VIA,     PCI_DEVICE_ID_82C586_1