IDE Seek Errors after kernel upgrade

Mark Hahn hahn at
Mon Jun 18 10:19:34 EDT 2001

> When I did I started getting these IDE errors (x4)


> kernel: hdc: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> kernel: hdc: dma_intr: error=0x84 { DriveStatusError BadCRC }          

badcrc is a warning that the disk/controller detected a corruption
of a transmission, and automatically retried it.  it only happens
if the cable is noisy (or, equivalently, if the cable is not capable
of supporting the transfer rate, too long, has a stub, etc).
occasional crc warnings are harmless.

> It is possible that SeekComplete errors are due to some difficulty that
> the drive has in tracking the servo signal in a few spots.  Not
> accessing those spots gets around the problem.

no.  badcrc's have nothing to do with any disk operation - 
they're strictly a cable/mode/noise problem.

> I don't know the way around it, other than to upgrade
> to a 2.4 kernel?  I would like it to use DMA still.

check you cable first: all IDE cables must be <=18", with both ends
plugged in.  for anything above udma33 (mode2 udma), you also need 
the new 80-conductor cable (which doesn't hurt lower speeds.)

if the warnings are too frequent, you should probably force a lower
transfer rate, since this is just a risetime/overshoot-type noise
issue.  hdparm lets you check and set the mode.

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