[Intel-gfx] [PATCH 1/2] drm/i915: add fbc enable flag, but disable by default

[Jesse Barnes]

On Thu, 05 May 2011 18:07:43 -0400
Adam Jackson <ajax at redhat.com> wrote:

> On 5/5/11 5:42 PM, Jesse Barnes wrote:
> > FBC has too many corner cases that we don't currently deal with, so
> > disable it by default so we can enable more important features like RC6,
> > which conflicts in some configurations.
> >
> > Signed-off-by: Jesse Barnes<jbarnes at virtuousgeek.org>
> 
> It's a bit weird to ...
> 
> > +unsigned int i915_enable_fbc = 0;
> > +module_param_named(i915_enable_fbc, i915_enable_fbc, int, 0600);
> > +
> 
> ... disable fbc by default ...
> 
> > +	if (!i915_enable_fbc) {
> > +		DRM_DEBUG_KMS("fbc disabled manually\n");
> > +		dev_priv->no_fbc_reason = FBC_MANUAL_DISABLE;
> > +		goto out_disable;
> > +	}
> 
> ... and then claim the user is to blame.

Yeah suppose I could use something like "fbc disabled per module
param".  We just have no way of knowing whether the user passed
i915_enable_fbc = 0 or the default was taken.

-- 
Jesse Barnes, Intel Open Source Technology Center