Mailing List Archive

Andrew Gaydenko wrote:
> OK, after multiple comments at this mailing list I have successfully
> moved to nptl. Thanks to all! I haven't noticed any issues yet.
>
> Now, I'll be happy to get some comments regarding moving from devfs
> to udev - experience, possible issues, ... If I understand well, some
> words about hardware/kernel/drivers under using do matter here:
>
> - ATA IDE
> - CD-RW/DVD IDE drives
> - USB mouse
> - USB printer (gdi driver)
> - ALSA (ice1724 driver), using it with JACK
> - nvidia driver
> - last gentoo-dev-sources
> - all other is synced with portage (~x86)
>
> And, besides of moving from officially obsolete feature, are there some
> advantages? - again, for desktop using.
>
> Andrew
>
> --
> gentoo-user@gentoo.org mailing list
>

The main advantage I see, is in having stable symlinks to USB devices. For
example, using a second printer it depends on the order they're plugged into
the box to get the lpX-nodes assigned to them. udev takes care of this and
assignes always the name to a special device you defined by a rule.

This comes in very handy if you have a digital camera and an USB stick. udev
can make sure that the stick is always accessible with /dev/stick, while the
camera always gets /dev/camera. As symlink or node, whatever name you want,
you decide.

So far my migration to udev went without problems, but I don't have an USB
printer, no nvidia card and I'm using the stable tree. But I don't think
that you will have problems, gentoo has equipped udev with a set of configs
which make it act mostly as if it were devfs, but with all the benefits it
brings with it.

Greetings,
Felix

On Sun, 19 Sep 2004 14:01:33 +0200, Felix Tiede <lists@pc-tiede.de> wrote:

[ snips ]

>
>
> Andrew Gaydenko wrote:

> > Now, I'll be happy to get some comments regarding moving from devfs
> > to udev - experience, possible issues, ...
> > And, besides of moving from officially obsolete feature, are there some
> > advantages? - again, for desktop using.
> >

> The main advantage I see, is in having stable symlinks to USB devices.
>
> So far my migration to udev went without problems,

Felix has covered the principle advantage of udev over devfs. The
other advantage is that devfs is now deprecated; it is extremely
unlikely that kernel developers will respond to bug reports. udev is
the wave of the future (not too distant) and actively maintained.

udev works in conjunction with hotplug, and there are some
deficiencies. In my case with al alsa-supported sound card, I have to
preload the alsa oss support modules, or udev/hotplug will not
generate the /dev/dsp, etc., nodes. Similar action is usually required
for the nvidia binary modules.

Once you have worked out little details like this, you can forget
about udev; it just works (tm). Back in the early days of udev (at
least 6 months ago) there were some noxious versions of udev, but the
bugs were corrected rapidly. Now udev is just ho-hum, business as
usual.

HTH,

--
/\/\
(CR) Collins Richey
\/\/ "I hear you're single again." "Spouse 2.0 had fewer bugs than
Spouse 1.0, but the maintenance ... was too much for my OS."
- Glitch (tm)

--
gentoo-user@gentoo.org mailing list

Collins Richey wrote:
> On Sun, 19 Sep 2004 14:01:33 +0200, Felix Tiede <lists@pc-tiede.de> wrote:
>
> [ snips ]
>
>
>>
>>Andrew Gaydenko wrote:
>
>
>>>Now, I'll be happy to get some comments regarding moving from devfs
>>>to udev - experience, possible issues, ...
>>>And, besides of moving from officially obsolete feature, are there some
>>>advantages? - again, for desktop using.
>>>
>
>
>>The main advantage I see, is in having stable symlinks to USB devices.
>>
>>So far my migration to udev went without problems,
>
>
> Felix has covered the principle advantage of udev over devfs. The
> other advantage is that devfs is now deprecated; it is extremely
> unlikely that kernel developers will respond to bug reports. udev is
> the wave of the future (not too distant) and actively maintained.
>
> udev works in conjunction with hotplug, and there are some
> deficiencies. In my case with al alsa-supported sound card, I have to
> preload the alsa oss support modules, or udev/hotplug will not
> generate the /dev/dsp, etc., nodes. Similar action is usually required
> for the nvidia binary modules.
>
> Once you have worked out little details like this, you can forget
> about udev; it just works (tm). Back in the early days of udev (at
> least 6 months ago) there were some noxious versions of udev, but the
> bugs were corrected rapidly. Now udev is just ho-hum, business as
> usual.
>
> HTH,
>

I moved to udev from devfs. Didn't notice anything different as I don't
have any external thingies to plug into my computer except now I can go
"ah ... you're *still* using devfs ... how cute!"
Just kidding. If you're like me without any external devices, you can
think of udev vs devfs like xorg vs xfree (a few months ago not
considering 6.8.0 and it's heavnly gift of true transparency). It's the
way to go. You won't notice anything different now, but when in the long
run it will pay up.

--

Adi

--
gentoo-user@gentoo.org mailing list

On Mon, 20 Sep 2004 03:25:57 +0300, Adrian CAPDEFIER
<adriancapdefier@digifin.ro> wrote:

> I moved to udev from devfs. Didn't notice anything different as I don't
> have any external thingies to plug into my computer except now I can go
> "ah ... you're *still* using devfs ... how cute!"
> Just kidding. If you're like me without any external devices, you can
> think of udev vs devfs like xorg vs xfree (a few months ago not
> considering 6.8.0 and it's heavnly gift of true transparency). It's the
> way to go. You won't notice anything different now, but when in the long
> run it will pay up.
>

Mostly true, but as I noted, my soundcard is not an "external thingy,"
but it still needs additional handholding under udev.

--
/\/\
(CR) Collins Richey
\/\/ "I hear you're single again." "Spouse 2.0 had fewer bugs than
Spouse 1.0, but the maintenance ... was too much for my OS."
- Glitch (tm)

--
gentoo-user@gentoo.org mailing list

Collins Richey wrote:
> Mostly true, but as I noted, my soundcard is not an "external thingy,"
> but it still needs additional handholding under udev.
>

You're right there :)
What sound card do you have? I have an onboard one with intel8x0 chipset
(I may be wrong here as soundcards/videocards (hei I bought ATI) are not
my thing) and 5.1 with alsa has been eluding me.
Is there any way to get such a sound card to output 5.1 or must I buy
another one? Which one do you people recommend?

--

Adi

--
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