public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Dan Williams <dcbw@redhat.com>
To: Greg KH <greg@kroah.com>
Cc: Chuck Ebbert <cebbert@redhat.com>,
	linux-kernel@vger.kernel.org, stable@kernel.org
Subject: Re: [stable]  A patch in 2.6.27.9 caused device names to change
Date: Tue, 03 Feb 2009 09:50:11 -0500	[thread overview]
Message-ID: <1233672611.11344.6.camel@localhost.localdomain> (raw)
In-Reply-To: <20090203000529.GC9467@kroah.com>

On Mon, 2009-02-02 at 16:05 -0800, Greg KH wrote:
> On Mon, Feb 02, 2009 at 05:02:38PM -0500, Chuck Ebbert wrote:
> > This patch:
> > http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git;a=blob_plain;f=releases/2.6.27.9/usb-option-add-pantech-cards.patch;hb=HEAD
> > 
> > replaced my wireless adapter's /dev/ttyACM0 interface with three interfaces:
> > /dev/ttyUSB[012]
> > 
> > That broke my ppp connection scripts. And I have to use /dev/ttyUSB1 to connect,
> > not USB0. Also it looks like Network Manager only knows how to use the first
> > interface in its auto-connect mode, so people using that also lost their
> > connections.
> 
> Ugh, that sucks.
> 
> That is what is also in upstream, so 2.6.29-rc also fails for you?
> 
> Dan, what's with replacing working devices with the cdc-acm driver with
> option device ids?  Is there some reason you did this?

For a long time we've been operating under the assumption that mobile
broadband devices should be driven by option and sierra, since those
drivers had the necessary buffering optimizations to support
higher-speed mobile broadband devices.  That was true at least up until
2.6.24.

Furthermore, up until this point, I have not seen mobile broadband
adapters (that aren't cellphones connected via USB) that *are* CDC-ACM
compliant.  Everything previously has advertised proprietary interfaces,
some of which are serial ports and some of which are not.

Most mobile broadband cards *do* have more than one TTY, the others are
used for additional control ports or proprietary access for stuff like
GPS and flashing the firmware.

Can we get the 'lsusb -v' output for this card?  I'm quite curious how
many endpoints and interfaces the device actually has.

Plus, are we expected to keep device names stable these days?  cdc-acm
is the catch-all driver, but if that driver is more "generic" and a
better driver is found, can we not update IDs just because the device
name may change?

Dan



  reply	other threads:[~2009-02-03 14:51 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-02 22:02 [stable] A patch in 2.6.27.9 caused device names to change Chuck Ebbert
2009-02-03  0:05 ` Greg KH
2009-02-03 14:50   ` Dan Williams [this message]
2009-02-03 20:14     ` Chuck Ebbert
2009-02-03 20:43       ` Dan Williams
2009-02-04  0:03     ` Greg KH
2009-02-04  7:28       ` Oliver Neukum
2009-02-04 11:20     ` Oliver Neukum

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1233672611.11344.6.camel@localhost.localdomain \
    --to=dcbw@redhat.com \
    --cc=cebbert@redhat.com \
    --cc=greg@kroah.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox