whats an UDMA ICRC error ?

[Dan Nelson]

In the last episode (Jun 03), Andreas Klemm said:
> On Tue, Jun 03, 2003 at 01:23:35AM -0500, Dan Nelson wrote:
> > In the last episode (Jun 03), Andreas Klemm said:
> > > ad2: UDMA ICRC error cmd=read fsbn 74689079 of 74689079-74689206 retrying
> > > ad2: UDMA ICRC error cmd=read fsbn 74689079 of 74689079-74689206 retrying
> > > 
> > > What exactly does an UDMA ICRC error mean ? I think this is
> > > simply a read error. AFAIK an IDE disk doesn't have spare sectors
> > > or am I wrong ? How severe is this error ? What do you think ??
> > 
> > An ICRC error is an error detected by the IDE controller.  It
> > usually means a cabling problem, as a disk error would be reported
> > by the drive, not the controller.  From the ATA spec:
> > 
> >   ICRC shall be set to one if an interface CRC error has occurred
> >   during an Ultra DMA data transfer.  The content of this bit is
> >   not applicable for Multiword DMA transfers.
> > 
> > There are other error bits that indicate uncorrectable media errors.
>                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^
> Does this mean, that data corruption occurred ??

No; I'm just saying that the ATA spec has a lot of status/error bits :)
If you had physical data corruption you'd see something other than ICRC.
 
-- 
	Dan Nelson
	dnelson at allantgroup.com