Re: RFC: Starting a stable kernel series off the 2.6 kernel

Luke-Jr
2005-12-05T05:54:49Z

On Sunday 04 December 2005 23:22, Greg KH wrote:
> On Sun, Dec 04, 2005 at 04:46:31AM +0000, Luke-Jr wrote:
> > Well, devfs does have some abilities udev doesn't: hotplug/udev
> > doesn't detect everything, and can result in rarer or non-PnP devices
> > not being automatically available;
>
> Are you sure about that today?

Nope, but I don't see how udev can possibly detect something that doesn't let
the OS know it's there-- except, of course, loading the driver for it and
seeing if it works.

> And udev wasn't created to do everything that devfs does.

Which might be a case for leaving devfs in. *shrug*

> And devfs can't do everything that udev can (by far...)

Didn't say it could...

> > Interesting effects of switching my desktop from devfs to udev:
> > 1. my DVD burners are left uninitialized until I manually modprobe ide-cd
> > or (more recently) ide-scsi
>
> Sounds like a broken distro configuration :)

Well, I was assuming you kept Gentoo's udev packages up to date. ;)
[ebuild R ] sys-fs/udev-070-r1 (-selinux) -static 429 kB

> > devfs also has the advantage of keeping the module info all in one
> > place-- the kernel or the module.
> > In particular, with udev the detection and /dev info is scattered into
> > different locations of the filesystem. This can probably be fixed
> > easily simply by having udev read such info from modules or via a /sys
> > entry, though.
>
> What information are you talking about here?

I'm assuming everything in /etc/udev/rules.d/50-udev.rules used to be in the
kernel for devfs-- perhaps it was PAM though, I'm not sure.
Other than that, I don't expect that simply installing a new kernel module
will allow the device to be detected automatically, but that some hotplug or
udev configurations will need to be updated also.
--
Luke-Jr
Developer, Utopios