From: Kay Sievers <kay.sievers@vrfy.org>
To: linux-hotplug@vger.kernel.org
Subject: Re: udev / hotplug / hald / dbus
Date: Thu, 09 Dec 2004 17:32:53 +0000 [thread overview]
Message-ID: <1102613573.6848.12.camel@localhost.localdomain> (raw)
In-Reply-To: <20041209171538.GB17970@fmp.com>
On Thu, 2004-12-09 at 11:15 -0600, Lindsay Haisley wrote:
> I'd like to know how the udev / hotplug mechanism works with the hald / dbus
> hardware abstraction/detection/notification system which is apparently
> becoming the defacto standard in Gnome. It looks as if there may be some
> duplication of effort here, at some level. I had to disable my auto device
> mounts in /etc/dev.d after I recently updated gnome and had to install hald
> and the dbus-daemon to get features in Gnome to work, such as auto-detection
> of CD-RW disks. It looks as if auto-detection and mounting of USB storage
> devices is also supported and enabled by hald / dbus, at least in Gnome.
>
> I'm certainly no expert in these matters, and the answer may be obvioius to
> anyone with more experience at a hardware level, but it looks as if there
> may be some functional overlap and possibly potential for conflict with
> these two systems.
The kernel creates/removes devices. The information about that is
exposed in sysfs. Changes in sysfs are notified from the kernel to
userspace by executing /sbin/hotplug.
udev is a devfs implementation. It uses the events and sysfs to maintain
the /dev directory. On node creation/removal the dev.d/ scripts are
called.
HAL also listens to the hotplug events and gets the name of the created
node from udev. HAL is a hardware abstraction that keeps it's own device
list inside a daemon, based on the events hotplug sends.
HAL's string based interface is easy to use from any application, cause
the D-BUS IPC can inform any application interested in device changes.
An application can subscribe to certain device events or a whole class
of device events.
One example of a HAL subscriber is the gnome-volume-manager, which can
mount your devices automatically. I don't see any overlap, besides your
own dev.d/ script. :)
Kay
-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://productguide.itmanagersjournal.com/
_______________________________________________
Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel
prev parent reply other threads:[~2004-12-09 17:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-09 17:15 udev / hotplug / hald / dbus Lindsay Haisley
2004-12-09 17:32 ` Kay Sievers [this message]
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=1102613573.6848.12.camel@localhost.localdomain \
--to=kay.sievers@vrfy.org \
--cc=linux-hotplug@vger.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;
as well as URLs for NNTP newsgroup(s).