Re: dma errors

["Daniel B." <REMOVEdanielCAPS@fgm.com>]

Greg Madden wrote:
...
> John Schmidt <jaschmidt@uofu.net> wrote:
...
> > I have two IDE drives ...  the motherboard is quite old.
...
> > I get the following error messages from dmesg:
...>> hde: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> > hde: dma_intr: error=0x84 { DriveStatusError BadCRC }
> > ide: failed opcode was: unknown
> > hde: dma_timer_expiry: dma status == 0x20
> > hde: DMA timeout retry
> > PDC202XX: Primary channel reset.
> > PDC202XX: Secondary channel reset.
> > hde: timeout waiting for DMA
> > hde: dma_timer_expiry: dma status == 0x21
> > hde: DMA timeout error
> > hde: dma timeout error: status=0x58 { DriveReady SeekComplete
> > DataRequest } ide: failed opcode was: unknown
...
> > What would be the source of these errors and how should I go about
> > fixing them?
>
> A couple of things, the generic IDE driver doesn't do dma , make sure
> you load the module for your chipset. Using 'hdparm' will
> show if dma is set for the drives.

Greg:

Clearly John's driver is doing DMA; otherwise all the DMA errors
wouldn't be present.


John:

Which motherboard do you have?

I have had similar problems with an Asus A7M266-D motherboard with multiple
kernel versions (2.2 through 2.6, I think).

From what I've been able to gather, my motherboard's IDE controller (AMD
768?) is buggy, and the Linux kernel doesn't do whatever the Windows
kernel does to work around the problem.

(I can't run the disks attached to the onboard IDE controller at full
sped (i.e., with DMA on) or I get extreme filesystem corruption in Linux.
Under Windows, I can run a seemingly full speed without any data-
corruption problems.)

Daniel