2.4.21 IDE problems (lost interrupt, bad DMA status)

[Marek Michalkiewicz]

Hi,

After upgrading the kernel from 2.4.20 to 2.4.21, sometimes I see
the following messages:

hda: dma_timer_expiry: dma status == 0x24
hda: lost interrupt
hda: dma_intr: bad DMA status (dma_stat=30)
hda: dma_intr: status=0x50 { DriveReady SeekComplete }

It happens especially when there is a lot of disk I/O (which stops
for a few seconds when these messages appear), with three different
disks (very unlikely they all decided to die at the same time...),
one old ATA33 (QUANTUM FIREBALL SE8.4A) and two newer ATA100 disks
(WDC WD300BB-32CCB0, ST340015A).  IDE controller: VIA VT82C686B
on a MSI MS-6368L motherboard.

I don't remember seeing anything like that in any earlier 2.4.x
kernels.  Is this a known problem?  Is this anything dangerous -
should I disable UDMA for now to play it safe?

Thanks,
Marek