Re: Radeon DRM dom0 issues

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Jan 20, 2014 at 10:26:22AM -0500, Michael D Labriola wrote:
> Konrad Rzeszutek Wilk <konrad@darnok.org> wrote on 01/20/2014 10:14:36 AM:
> 
> > From: Konrad Rzeszutek Wilk <konrad@darnok.org>
> > To: Michael D Labriola <mlabriol@gdeb.com>, 
> > Cc: xen-devel@lists.xen.org, michael.d.labriola@gmail.com
> > Date: 01/20/2014 10:14 AM
> > Subject: Re: [Xen-devel] Radeon DRM dom0 issues
> > 
> > On Mon, Jan 20, 2014 at 09:58:32AM -0500, Michael D Labriola wrote:
> > > Anyone here running a dom0 w/ Radeon DRM?  I'm having consistent 
> crashes 
> > > with multiple older R600 series (HD 6470 and HD 6570) and unusably 
> slow 
> > > graphics with a newer HD7000 (can see each line refresh indiviually on 
> 
> > > radeonfb tty).  All 3 systems seem to work fine bare metal.
> > 
> > I hadn't been using DRM, just Xserver. Is that what you mean?
> 
> The R600 problems happen when in X, using OpenGL, on my dom0.  The 
> RadeonSI sluggishness is when using the KMS framebuffer device for a plain 
> text console login.

So sluggish is probably due to the PAT not being enabled. This patch
should be applied:

lkml.org/lkml/2011/11/8/406

(or http://marc.info/?l=linux-kernel&m=132888833209874&w=2)

and these two reverted:

 "xen/pat: Disable PAT support for now."
 "xen/pat: Disable PAT using pat_enabled value."

Which is to say do:

git revert c79c49826270b8b0061b2fca840fc3f013c8a78a
git revert 8eaffa67b43e99ae581622c5133e20b0f48bcef1

> 
> 
> > > 
> > > The R600 crashes happen seemingly randomly when using OpenGL 
> Compositor in 
> > > Enlightenment 0.17.  My dom0 need not even have any domUs running. 
> > > Sometimes it happens within a few minutes, sometimes it will run OK 
> for an 
> > > afternoon or so.  Eventually TTM issues an "unable to get page 0" 
> error 
> > > message, the radeon driver follows that up with a 
> > > "radeon_gem_object_create failed to allocate gem" error message.  Then 
> the 
> > > radeon driver starts spamming that gem failure message until I'm 
> forced to 
> > > reboot.
> > > 
> > > Behavior is identical with kernel versions 3.8, 3.10, and 3.13-rc8.
> > > 
> > > I'm using Xen 4.2.1 32bit.
> > > 
> > > xen command line is:  vga=mode=0x314
> > > kernel command line is:  root=/dev/md0 quiet pci=realloc 
> > > console=ttyS0,115200n8 console=tty0
> > > 
> > > Fingers crossed that there's some magic boot parameter I'm missing. 
> It's 
> > > been a while since I dabbled with this stuff.  ;-)
> > 
> > That should have been working. I had been using Xserver for years now.
> > Just to make sure - you aren't referring to running with X right? Just
> > simple framebuffer?
> 
> I'm not sure I understand the delineation between Xserver and X...  I am 
> indeed in X, using xf86-video-ati and Mesa for OpenGL support.  I've been 
> doing this for years as well, but with nouveau and w/out 3d support.  Was 
> kinda hoping that the Radeon cards I got a hold of would allow for 
> hardware accelerated 3d on my dom0.

You should be able to use 3D as well - with those said patches.

> 
> I just tried adding 'nopat' to the kernel command line.  I remember doing 
> that a year ago... don't recall why.  Any chance that helps?

Heh. So you want the inverse with a patch that fixes the PAT wreaking
havoc.
> 
> ---
> Michael D Labriola
> Electric Boat
> mlabriol@gdeb.com
> 401-848-8871 (desk)
> 401-848-8513 (lab)
> 401-316-9844 (cell)
> 
> 
> 
>  
> 
> 
> 
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