Re: IDE/ATAPI in 2.5

[H. Peter Anvin]

Followup to:  <[e-mail]>
By author:    Erik Andersen <[e-mail]>
In newsgroup: linux.dev.kernel
>   
> Of course making user space do this is pretty lame.  But we
> have a much better way.  Each cdrom device registers with the
> uniform cdrom driver, which can easily assign each registered
> cdrom device a major and minor.  That scanning for cdroms would
> be as simple as
>     for i in /dev/cdrom* ; do
> 	open ($i, O_RDONLY|O_NONBLOCK)) < 0) {
> 	    /* Found a cdrom drive */
> 	}
>     

Yes, something like that would be nice.

However, the case still remains that I think Linus' proposed overall
packet infrastructure is the right thing to do.  That way a uniform
API would be available for poking at any device that supports MMC (is
that the correct term these days?) commands, regardless of the type
of device and the lower-level transports.

People have -- correctly -- corrected me on the "ATAPI = SCSI over
IDE" issue.  When I think of SCSI, I tend to think of what a network
engineer would call "the upper data link layer", i.e. the command
packet frame format.  I did not mean to imply that the physical
interface (PHY), or the lower data link layer (MAC) where the same.  I
also realize that there are differences, but *from what I've seen*
they seem to be relatively minor.

I meant to start a discussion, not "call a vote", especially not
w.r.t. the lower-level implementation details.

	-hpa

-- 
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http://www.zytor.com/~hpa/puzzle.txt	<[e-mail]>