Re: Pioneer DVD 114 vs. 2.2.5 ide driver

Jens Axboe (axboe@image.dk)
Tue, 28 Sep 1999 19:53:58 +0200


On Tue, Sep 28 1999, Derek J. Balling wrote:
> > > hdc: ATAPI 0X DVD-ROM drive, 512kB Cache
> >
> >The 103S Pioneer DVD drive reports 0 speed as well. Don't worry
> >about it, it has no effect on its performance.
>
> I think the point he's making is that, regardless of whether it affects
> performance or not, it's the wrong speed figure. I freely admit to not
> knowing the first thing about the code (I lurk on linux-kernel mainly to
> keep abreast of what's new and upcoming, not because I have any C
> programming skill), but if this is a commonality to DVD drives, then why
> not just skip reporting the speed entirely. (e.g., report "hdc: ATAPI
> DVD-ROM drive, 512kB Cache"). Or, alternatively, if the speed is "0", skip
> the speed (since we know that unless your CD-ROM is broken, it's probably
> faster than zero-speed *g*)
>
> Just $0.02 worth from the peanut gallery.

The speed figure comes out of the capabilities page and as
such I just have to believe what the drive tells me. DVD drives
are covered by newer specs (Mt Fuji / MMC) that report the
cap page as being deprecated, but considering the huge gaps
drives otherwise exhibit wrt these specs, I'm suprised that
Pioneer decided to drop the speed listing all together. A
more fancy speed reading can be obtained through the newer
GET_PERFORMANCE command, but I'm not going to look at that
merely for reporting a more "correct" max speed.

-- 
*  Jens Axboe <axboe@image.dk>
*  Linux CD-ROM Maintainer
*  http://www.kernel.dk

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