Re: [bk tree] DRM add a version check.. for 2.6.12 (distro kernel maintainers + drm users plz read also...)

[Matti Aarnio <matti.aarnio@zmailer.org>]

Dropping Linus off this list...

On Mon, Mar 28, 2005 at 12:40:16PM +0100, Dave Airlie wrote:
> Hi Linus,
> 
> In order to stop someone loading a drm driver on a wrong core this patch
> makes the driver pass in the version is was built against, this mainly
> useful for people using the DRI snapshots for cards that aren't their
> normal cards...
> 
> Also for anyone who maintains a kernel for distros or builds their own
> please build your kernels with CONFIG_DRM=m not =y, from 2.6.11 onwards..
> as if you build with =y then DRI snapshots will no longer work..

I tried 2.6.12-rc2 which includes this patch, and I get DRM failures
here, which causes application and X to hang.  (I got failures with 2.6.11
also.) 

When accessing the machine from network, I can see that either application,
or X itself is running as close as possible to 100% CPU utilization.

Symptom is such that the application, or X-server, is executing an ioctl()
on a file-handle that has node:   /dev/drm/card0    open in r/w mode.

Following is from memory:

    ioctl(5, something, something)
    -- Received ALARM(0) --
    ioctl(5, something, something)
    -- Received ALARM(0) --

that repeats as fast as possible.

I have now  Radeon 9200SE card with 128 MB memory (I used to have Matrox
MGA G400 AGP with 8 MB memory - no room for anything but pixel maps), but
then I absolutely needed accelerated 3D, and had to go and get a "modern"
card.

System is running  Fedora Core 4 Test-1  application space codes along
with fresh baseline 2.6.11 + 2.6.12-rc2 patchset ( = "2.6.12-rc2" ).


I observed that xscreensaver-demo running "GLForestFire" is reliably
able to hangup the desktop within minutes, IF media-automounter is
snooping around in /dev/cdrom and there is some disk.  (I had FC4test1
rescue disk in there. )

With disk taken out, the system ran some 8 hours without a glitch.

Nevertheless, I then tried some fun with TuxRacer, and was able to
get the same drm hangup after an hour or so.


ANY ideas ?

/Matti Aarnio