Re: [PATCH] drm/i915: Sanitize the enable_ppgtt module option once

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 23 Apr 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Wed, Apr 23, 2014 at 11:37:46AM +0300, Jani Nikula wrote:
>> On Tue, 22 Apr 2014, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>> > Otherwise we'll end up spamming dmesg on every context creation on snb
>> > with vt-d enabled. This regression was introduced in
>> >
>> > commit 246cbfb5fb9a1ca0997fbb135464c1ff5bb9c549
>> > Author: Ben Widawsky <benjamin.widawsky@intel.com>
>> > Date:   Fri Dec 6 14:11:14 2013 -0800
>> >
>> >     drm/i915: Reorganize intel_enable_ppgtt
>> >
>> > References: https://lkml.org/lkml/2014/4/17/599
>> > Cc: Alessandro Suardi <alessandro.suardi@gmail.com>
>> > Cc: Ben Widawsky <ben@bwidawsk.net>
>> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>> > ---
>> >  drivers/gpu/drm/i915/i915_gem_gtt.c | 26 +++++++++++++++++++-------
>> >  1 file changed, 19 insertions(+), 7 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> > index 0d514ff9b94c..47491c4a1181 100644
>> > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
>> > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> > @@ -34,25 +34,35 @@ static void gen8_setup_private_ppat(struct drm_i915_private *dev_priv);
>> >  
>> >  bool intel_enable_ppgtt(struct drm_device *dev, bool full)
>> >  {
>> > -	if (i915.enable_ppgtt == 0 || !HAS_ALIASING_PPGTT(dev))
>> > +	if (i915.enable_ppgtt == 0)
>> >  		return false;
>> >  
>> >  	if (i915.enable_ppgtt == 1 && full)
>> >  		return false;
>> >  
>> > +	return true;
>> > +}
>> > +
>> > +static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
>> > +{
>> > +	if (enable_ppgtt == 0 || !HAS_ALIASING_PPGTT(dev))
>> > +		return 0;
>> > +
>> > +	if (i915.enable_ppgtt == 1)
>> > +		return 1;
>> > +
>> > +	if (i915.enable_ppgtt == 2 && HAS_PPGTT(dev))
>> > +		return 2;
>> 
>> You should probably either pass enable_ppgtt as parameter and use that
>> exclusively, or not pass it and refer to i915.enable_ppgtt directly, but
>> not mix them.
>
> New patch on its way with Chris' comments also applied.
>> 
>> > +
>> >  #ifdef CONFIG_INTEL_IOMMU
>> >  	/* Disable ppgtt on SNB if VT-d is on. */
>> >  	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped) {
>> >  		DRM_INFO("Disabling PPGTT because VT-d is on\n");
>> > -		return false;
>> > +		return 0;
>> >  	}
>> >  #endif
>> >  
>> > -	/* Full ppgtt disabled by default for now due to issues. */
>> > -	if (full)
>> > -		return HAS_PPGTT(dev) && (i915.enable_ppgtt == 2);
>> > -	else
>> > -		return HAS_ALIASING_PPGTT(dev);
>> > +	return HAS_ALIASING_PPGTT(dev) ? 1 : 0;
>> 
>> 
>> This conflicts in -fixes due to
>> commit 8d214b7d9c45f4af23ce41b2bc74f79c44f760de
>> Author: Ben Widawsky <benjamin.widawsky@linux.intel.com>
>> Date:   Mon Mar 24 18:06:00 2014 -0700
>> 
>>     drm/i915: Allow full PPGTT with param override
>> 
>> Should I incorporate that in the conflict resolution for simplicity,
>> letting 3.15 users also play with full ppgtt with the module param?
>
> Yeah I guess it's easiest to just cherry-pick that one to -fixes, too.
> -Daniel

Pushed v2 to -fixes, along with "drm/i915: Allow full PPGTT with param
override". Thanks for the patch and review.

BR,
Jani.


>
>> 
>> 
>> BR,
>> Jani.
>> 
>> 
>> >  }
>> >  
>> >  
>> > @@ -1157,6 +1167,8 @@ int i915_gem_init_ppgtt(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt)
>> >  	struct drm_i915_private *dev_priv = dev->dev_private;
>> >  	int ret = 0;
>> >  
>> > +	i915.enable_ppgtt = sanitize_enable_ppgtt(dev, i915.enable_ppgtt);
>> > +
>> >  	ppgtt->base.dev = dev;
>> >  	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
>> >  
>> > -- 
>> > 1.9.2
>> >
>> > _______________________________________________
>> > Intel-gfx mailing list
>> > Intel-gfx@lists.freedesktop.org
>> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> 
>> -- 
>> Jani Nikula, Intel Open Source Technology Center
>
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Jani Nikula, Intel Open Source Technology Center