Date: Mon, 30 Dec 1996 12:43:40 -0800 From: Julian Elischer <julian@whistle.com> To: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de> Cc: FreeBSD hackers <freebsd-hackers@freebsd.org>, Randy Terbush <randy@zyzzyva.com> Subject: Re: DEVFS strangeness Message-ID: <32C8297C.446B9B3D@whistle.com> References: <199612301840.TAA09551@uriah.heep.sax.de>
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J Wunsch wrote:
>
> As Randy Terbush wrote:
>
> > Is this a known deficiency of the DEVFS?
>
> No, it's a known (now that you mention it :) deficiency of the sound
> driver. A quick glance over the source yields:
Randy:
When I added devfs support to all teh devices, I had to add it to
some devices that I didn't understand very well. the sound drivers came
under
this catagory.
I guess I didn't understand it as well as I thought I did.
you just need to fix the sections of code marked with #ifdef DEVFS
there are man pages in chapter 9 for the devfs entrypoints..
if you have hte time to experiment, you migh tbe the perfect person
to submit the patches.
>
> static int
> sndattach (struct isa_device *dev)
> {
> int unit;
> ...
>
> unit = driver_to_voxunit(dev->id_driver);
> ...
>
> #ifdef DEVFS
> /* XXX */ /* find out where to store the tokens.. */
> /* XXX */ /* should only create devices if that card has them */
> #define SND_UID 0
> #define SND_GID 13
>
> snd_devfs_token[unit]=
> devfs_add_devswf(&snd_cdevsw, (unit << 4)+SND_DEV_CTL, DV_CHR,
> ^^^^
> SND_UID, SND_GID, 0660, "mixer%d", unit);
> ^^ ^^^^
>
> However:
>
> static int
> driver_to_voxunit(struct isa_driver *driver)
> {
> /* converts a sound driver pointer into the equivalent
> VoxWare device unit number */
> if(driver == &opldriver)
> return(SNDCARD_ADLIB);
> else if(driver == &sbdriver)
> return(SNDCARD_SB);
> else if(driver == &pasdriver)
> return(SNDCARD_PAS);
> etc. pp....
>
> So this driver seems to have to very different ideas of what a `unit'
> might be. If it would really use the term `unit' consistently in the
> above sense, it should recognize it always as being unit 4. Probably,
> the unit # in the DEVFS sense can only be 0 at all for this driver,
> however.
>
> I think this idea of a unit # is a gross abuse... If i read this
> correctly, it would never be possible to put two identical soundcards
> into the same machine (on different hardware addresses and interrupt
> vectors, i mean)?
I think you are right..
Maybe we should take the latest drivers from amancio and the original
author
and import them, and FIX them :)
>
> --
> cheers, J"org
>
> joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
> Never trust an operating system you don't have sources for. ;-)
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