Subject: Re: Refactoring MI devices in GENERIC and friends
To: Michael Lorenz <macallan@netbsd.org>
From: Allen Briggs <briggs@netbsd.org>
List: tech-kern
Date: 09/09/2007 16:43:06
On Sat, Sep 08, 2007 at 05:37:45PM -0400, Michael Lorenz wrote:
> assuming if it's not in GENERIC it's not there is a mistake, it would 
> just indicate that the drivers in question likely haven't been tested 
> on those platforms.

This is a bigger point that you might imagine...  I found when working
on PowerPC and ARM systems that drivers that have not been used on
sparc/macppc/alpha/etc., probably don't work on other architectures.
The reasons have been mentioned elsewhere in this thread.  I say
"probably" because in my experience, each of a half-dozen or so drivers
that I tried needed a tweak here or there when I put them in a PowerPC
(BE or bus_dmamap_sync) or evbarm (bus_dmamap_sync) system.

None of the problems that I saw would be caught by a compile--only by
trying to use the hardware.  I don't have a real problem with including
devices in a compile, but making the leap to "supported" or "expected
to run" would be unconscionable.

If we do include them, how do we communicate (amongst ourselves and with
users) which drivers have been actually used successfully on a given
platform?

-allen

-- 
Allen Briggs  |  http://www.ninthwonder.com/~briggs/  |  briggs@ninthwonder.com