RE: The WHY's (RE: ide drive w/dma ... system crash)

Andre M. Hedrick (hedrick@Astro.Dyer.Vanderbilt.Edu)
Tue, 11 May 1999 23:23:19 -0500 (CDT)


On Wed, 12 May 1999, Guest section DW wrote:

> From goemon@sasami.anime.net Wed May 12 03:51:55 1999
>
> On Wed, 12 May 1999, Guest section DW wrote:
> > > So why would it report 33483/16/63 then. (Award BIOS)
> > Name the disk type,
>
> hdc: Maxtor 91728D8, 16479MB w/512kB Cache, CHS=33483/16/63, (U)DMA
>
> > the hdparm -I output,
>
> # /sbin/hdparm -i /dev/hdc
>
> /dev/hdc:
>
> Model=Maxtor 91728D8, FwRev=GAS54112, SerialNo=A805S1XC
> Config={ Fixed }
> RawCHS=33483/16/63, TrkSize=0, SectSize=0, ECCbytes=29
>
>
> Ah, you were cheated by Andre.

Cheated is a little hard.

> In the good old days `hdparm -i' gave interesting output.
> These days `hdparm -i' prints not what the disk says, but
> what the author of the IDE driver thought you would prefer to see.

Well we bang heads again.

> So, `hdparm -i' is completely worthless (for geometries) these days.

It is not worthless, as much as everyone wants to think that the original
sample of drive->id is never tampered with is still a dream. The only way
the kernel can even think about seeing beyond 8.4GB is the correct the CHS
and capacity. One should note that twiddling with drive->id was in place
long before the task of IDE maintainance was passed to me from Mark L.
Look into a pre 2.1.121 or older development kernel and you see that it
existed before I refined the tinker that is not finished.

> That is why I asked for `hdparm -I'.

The "-I" is preserved to allow us to interrigate the drive for the raw
values of the 512 sector_word.

> Let me predict that it will say
>
> # /sbin/hdparm -I /dev/hdc
>
> /dev/hdc:
>
> Model=aMtxro9 71828D, FwRev=AG5S1421, SerialNo=8A501SCX
> Config={ Fixed }
> RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=29
> ...
>
> and hence is not an exception. It really tells the world
> that it is 16383/16/63, entirely according to the standard.
>
> Andries
>

Andre Hedrick
The Linux IDE guy

http://www.dyer.vanderbilt.edu/server/udma/2.2.7.uniform-ide-6.19.patch.gz
http://www.dyer.vanderbilt.edu/server/udma/ide.2.0.37pre11+pat7.gz
http://www.dyer.vanderbilt.edu/server/udma/hdparm-3.5i.patch.gz

APC UPS Daemon Support Center.
http://www.brisse.dk/site/apcupsd/
GPLed source on April 7, 1999

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