Re: [PATCH] 2.5.18 IDE 73

Linus Torvalds (torvalds@transmeta.com)
Thu, 30 May 2002 08:25:09 -0700 (PDT)


On 30 May 2002, Alan Cox wrote:
>
> > And last but not least: some devices which should be viewd as "same type"
> > are hooked up to different major numbers instead of sharing them.
> > Most prominent here are the differences between SCSI disks and ATA disks
> > for example. From a technical point of view they don't make *any* sense.
>
> Linus has explicitly stated he wants to do this and make all disks
> appear the same and the same place. It actually makes lots of sense.

It should be a lot easier these days, and we should be fairly close.

A device driver should really _never_ see a "device number". It should see
a request queue and a disk/controller index, so that we can arbitrarily
map different device numbers to different devices (or sometimes to the
_same_ device).

But yes, there are lots of device drivers that right now use the device
number to get the disk/controller index by themselves, so right now the
minor/major numbers mean a bit too much.

Linus

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