From: "Jon Smirl" <jonsmirl@gmail.com>
To: "Greg KH" <greg@kroah.com>
Cc: "Ian Romanick" <idr@us.ibm.com>, "Dave Airlie" <airlied@linux.ie>,
"Arjan van de Ven" <arjan@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: Re: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access
Date: Fri, 5 May 2006 16:43:15 -0400 [thread overview]
Message-ID: <9e4733910605051343k3213d3f6ma4673ab0650272ea@mail.gmail.com> (raw)
In-Reply-To: <9e4733910605051335h7a98670ie8102666bbc4d7cd@mail.gmail.com>
> On 5/5/06, Greg KH <greg@kroah.com> wrote:
> > Who cares who "enabled" the device. Remember, the majority of PCI
> > devices in the system are not video ones. Lots of other types of
> > devices want this ability to enable PCI devices from userspace. I've
> > been talking with some people about how to properly write PCI drivers in
> > userspace, and this attribute is a needed part of it.
The problem is not who 'enabled' the device. The problem is who owns
the state that has been loaded into the device. Without a mechanism
like open there is no way to serialize the programs trying to set
state into the device.
fbdev and X have this fight currently. On every VT swap they each
reload their state into the video hardware. There is no coordination
so both systems have to assume worst case and rebuild everything. This
is not a good environment to program in. Every time one of the systems
starts using some new feature of hardware (like acceleration
functions) new state recovery code needs to be written.
--
Jon Smirl
jonsmirl@gmail.com
next prev parent reply other threads:[~2006-05-05 20:43 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-29 8:46 Arjan van de Ven
2006-04-29 8:51 ` Andrew Morton
2006-04-29 8:59 ` Arjan van de Ven
2006-04-29 9:04 ` Dave Airlie
2006-05-02 16:14 ` Bjorn Helgaas
2006-05-02 16:21 ` Greg KH
2006-05-02 16:51 ` Jesse Barnes
2006-05-04 19:09 ` Bjorn Helgaas
2006-05-04 19:11 ` Arjan van de Ven
2006-05-04 19:26 ` Bjorn Helgaas
2006-05-04 19:42 ` Matthew Garrett
2006-05-04 20:40 ` Jon Smirl
2006-05-04 21:05 ` Peter Jones
2006-05-04 21:17 ` Martin Mares
2006-05-04 21:29 ` Peter Jones
2006-05-04 21:37 ` Martin Mares
2006-05-04 21:38 ` Jon Smirl
2006-05-04 23:22 ` Peter Jones
2006-05-05 19:20 ` Ian Romanick
2006-05-05 20:14 ` Jon Smirl
2006-05-05 20:26 ` Greg KH
2006-05-05 20:35 ` Jon Smirl
2006-05-05 20:43 ` Jon Smirl [this message]
2006-05-05 21:10 ` Greg KH
2006-05-05 21:06 ` Greg KH
2006-05-05 21:15 ` Jon Smirl
2006-05-05 22:27 ` Greg KH
2006-05-06 0:05 ` Jon Smirl
2006-05-06 1:57 ` Dave Airlie
2006-05-06 3:39 ` Jon Smirl
2006-05-06 12:42 ` Krzysztof Halasa
2006-05-06 13:08 ` Jon Smirl
2006-05-06 18:10 ` Krzysztof Halasa
2006-05-06 18:24 ` Jon Smirl
2006-05-06 23:16 ` Krzysztof Halasa
2006-05-07 5:56 ` Kyle Moffett
2006-05-07 12:05 ` Krzysztof Halasa
2006-05-07 19:07 ` Kyle Moffett
2006-05-08 0:03 ` Krzysztof Halasa
2006-05-07 13:12 ` Pavel Machek
2006-05-08 14:26 ` Kyle Moffett
2006-05-08 14:54 ` Arjan van de Ven
2006-05-08 4:06 ` Dave Airlie
2006-05-08 5:27 ` Jon Smirl
2006-05-07 8:54 ` Adam Belay
2006-05-14 0:29 ` Benjamin Herrenschmidt
2006-05-14 0:56 ` Jon Smirl
2006-05-14 23:57 ` Benjamin Herrenschmidt
2006-05-15 0:14 ` Jon Smirl
2006-05-14 0:57 ` Patrick McFarland
2006-05-14 1:11 ` Jon Smirl
2006-05-04 21:18 ` Jon Smirl
2006-05-04 21:38 ` Peter Jones
2006-05-04 21:48 ` Jon Smirl
2006-05-04 21:57 ` Peter Jones
2006-05-04 22:05 ` Jon Smirl
2006-05-04 19:49 ` Arjan van de Ven
2006-05-15 2:10 ` Eric W. Biederman
2006-05-02 16:38 ` Jon Smirl
2006-05-02 16:45 ` Arjan van de Ven
2006-05-02 16:59 ` Jon Smirl
2006-05-02 17:00 ` Arjan van de Ven
2006-05-02 17:13 ` Jon Smirl
2006-05-02 18:27 ` Arjan van de Ven
2006-05-02 19:00 ` Jon Smirl
2006-05-02 19:29 ` Peter Jones
2006-05-02 21:40 ` Dave Airlie
2006-05-02 21:52 ` Jon Smirl
2006-05-02 23:36 ` Dave Airlie
2006-05-03 0:19 ` Matthew Wilcox
2006-05-03 0:26 ` Valdis.Kletnieks
2006-05-03 1:24 ` Jon Smirl
2006-05-03 1:30 ` Dave Airlie
2006-05-03 6:02 ` Arjan van de Ven
2006-05-03 13:23 ` Jon Smirl
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