lkml.org 
[lkml]   [2006]   [May]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access
Date
On Saturday 29 April 2006 03:04, Dave Airlie wrote:
>
> > This patch adds an "enable" sysfs attribute to each PCI device. When read it
> > shows the "enabled-ness" of the device, but you can write a "0" into it to
> > disable a device, and a "1" to enable it.
> >
> > This later is needed for X and other cases where userspace wants to enable
> > the BARs on a device (typical example: to run the video bios on a secundary
> > head). Right now X does all this "by hand" via bitbanging, that's just evil.
> > This allows X to no longer do that but to just let the kernel do this.
> >
> > Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
> > CC: Peter Jones <pjones@redhat.com>
> > CC: Dave Airlie <airlied@linux.ie>
>
> ACK
>
> This would allow me to remove the issue in X where loading the DRM at X
> startup acts differently than loading the DRM before X runs, due to Xs PCI
> probe running in-between... with this I can just enable all VGA devices
> and no worry whether they have a DRM or not..

This sysfs "enable" patch seems like goodness.

But I hope that when X uses this, it only enables & disables VGA
devices it's actually using. In the past, it seems like X has
blindly disabled *all* VGA devices in the system, even though
they might be in use by another X server. I'm sure that's all
well-understood and cleaned up now; just wanted to make sure
this nightmare didn't recur.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-05-02 18:17    [W:0.209 / U:0.072 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site