[Intel-gfx] [PATCH] drm/i915: refuse to load on gen6+ without kms

[Daniel Vetter]

On Mon, Mar 26, 2012 at 08:44:51PM +0100, Chris Wilson wrote:
> On Mon, 26 Mar 2012 21:33:18 +0200, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > Spurred by an irc discussion, let's start to clear up which parts of
> > our kms + ums/gem + ums/dri1 + vbios/dri1 kernel driver pieces
> > userspace in the wild actually uses.
> > 
> > The idea is that we introduce checks at entry-points (module load
> > time, ioctls, ...) first and then reap any obviously dead code in a
> > second step.
> > 
> > As a first step refuse to load without kms on chips where userspace
> > never supported ums. Now upstream hasn't supported ums on ilk, ever.
> > But RHEL had the great idea to backport the kms support to their ums
> > driver.
> > 
> > Cc: Dave Airlie <airlied at gmail.com>
> > Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> > ---
> >  drivers/gpu/drm/i915/i915_dma.c |   10 +++++++++-
> >  1 files changed, 9 insertions(+), 1 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> > index 64dfbb8..8567fdf 100644
> > --- a/drivers/gpu/drm/i915/i915_dma.c
> > +++ b/drivers/gpu/drm/i915/i915_dma.c
> > @@ -1955,9 +1955,17 @@ i915_mtrr_setup(struct drm_i915_private *dev_priv, unsigned long base,
> >  int i915_driver_load(struct drm_device *dev, unsigned long flags)
> >  {
> >  	struct drm_i915_private *dev_priv;
> > +	struct intel_device_info *info;
> >  	int ret = 0, mmio_bar;
> >  	uint32_t agp_size;
> >  
> > +	info = (struct intel_device_info *) flags;
> > +
> > +	/* Refuse to load on gen6+ without kms enabled. */
> > +	if (info->gen >= 6 && !drm_core_check_feature(dev, DRIVER_MODESET))
> > +		return -ENODEV;
> 
> The problem here is that this highlights that with the default
> configuration we have no driver for our current hardware in the kernel.

Well, with the default configuration we _do_ have no driver for our
hardware. Non-kms doesn't do anything really on it's own, and without any
userspace existing no-one will call the entervt or gem_init ioctls.

No change at all imo.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48