[PATCH] drm/radeon: don't init gpuvm if accel is disabled

[Deucher, Alexander]

> -----Original Message-----
> From: Gabbay, Oded
> Sent: Thursday, January 29, 2015 2:46 AM
> To: Alex Deucher; dri-devel at lists.freedesktop.org
> Cc: Deucher, Alexander; stable at vger.kernel.org
> Subject: Re: [PATCH] drm/radeon: don't init gpuvm if accel is disabled
> 
> 
> 
> On 01/28/2015 09:41 PM, Alex Deucher wrote:
> > If acceleration is disabled, it does not make sense
> > to init gpuvm since nothing will use it.  Moreover,
> > if radeon_vm_init() gets called it uses accel to try
> > and clear the pde tables, etc. which results in a bug.
> >
> > Bug:
> > https://bugs.freedesktop.org/show_bug.cgi?id=88786
> >
> > Signed-off-by: Alex Deucher<alexander.deucher at amd.com>
> > Cc:stable at vger.kernel.org
> Alex,
> What is accel ?

If the ring tests fail and for some reason the IPs (e.g., gfx or sdma) are not available, the driver disables acceleration and basically falls back to modesetting only.

> Is there a situation where accel is disabled and HSA should work ? e.g.
> headless
> mode ?

No.  We only disable acceleration if we can't get the IPs (gfx, sdma) initialized.  Headless has nothing to do with acceleration in this context.

Alex