Re: [Intel-gfx] [PATCH v27 2/6] drm/i915: Separate icl and skl SAGV checking

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, May 05, 2020 at 11:37:23PM +0300, Lisovskiy, Stanislav wrote:
> On Tue, May 05, 2020 at 02:01:16PM +0300, Ville Syrjälä wrote:
> > On Tue, May 05, 2020 at 01:42:46PM +0300, Ville Syrjälä wrote:
> > > On Tue, May 05, 2020 at 01:22:43PM +0300, Stanislav Lisovskiy wrote:
> > > > Introduce platform dependent SAGV checking in
> > > > combination with bandwidth state pipe SAGV mask.
> > > > 
> > > > v2, v3, v4, v5, v6: Fix rebase conflict
> > > > 
> > > > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/intel_pm.c | 30 ++++++++++++++++++++++++++++--
> > > >  1 file changed, 28 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > > > index da567fac7c93..c7d726a656b2 100644
> > > > --- a/drivers/gpu/drm/i915/intel_pm.c
> > > > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > > > @@ -3853,6 +3853,24 @@ static bool intel_crtc_can_enable_sagv(const struct intel_crtc_state *crtc_state
> > > >  	return true;
> > > >  }
> > > >  
> > > > +static bool skl_crtc_can_enable_sagv(const struct intel_crtc_state *crtc_state)
> > > > +{
> > > > +	struct intel_atomic_state *state = to_intel_atomic_state(crtc_state->uapi.state);
> > > > +	/*
> > > > +	 * SKL+ workaround: bspec recommends we disable SAGV when we have
> > > > +	 * more then one pipe enabled
> > > > +	 */
> > > > +	if (hweight8(state->active_pipes) > 1)
> > > > +		return false;
> > > 
> > > That stuff should no longer be here since we now have it done properly
> > > in intel_can_eanble_sagv().
> > > 
> > > > +
> > > > +	return intel_crtc_can_enable_sagv(crtc_state);
> > > > +}
> > > > +
> > > > +static bool icl_crtc_can_enable_sagv(const struct intel_crtc_state *crtc_state)
> > > > +{
> > > > +	return intel_crtc_can_enable_sagv(crtc_state);
> > > > +}
> > > 
> > > This looks the wrong way around. IMO intel_crtc_can_enable_sagv()
> > > should rather call the skl vs. icl variants as needed. Although we
> > > don't yet have the icl variant so the oerdering of the patches is
> > > a bit weird.
> > 
> > Do we even need an icl variant actually? Does it use the skl or tgl
> > way of checking for sagv yes vs. no?
> 
> As I undestand icl implementation should be pretty much the same as
> skl, except that icl doesn't have this one active pipe limitation
> thing.

Right, and since that's now moved into intel_can_enable_sagv() we can
use skl_crtc_can_enable_sagv() for all pre-tgl.

> 
> 
> Stan
> > 
> > > 
> > > > +
> > > >  bool intel_can_enable_sagv(const struct intel_bw_state *bw_state)
> > > >  {
> > > >  	if (bw_state->active_pipes && !is_power_of_2(bw_state->active_pipes))
> > > > @@ -3863,22 +3881,30 @@ bool intel_can_enable_sagv(const struct intel_bw_state *bw_state)
> > > >  
> > > >  static int intel_compute_sagv_mask(struct intel_atomic_state *state)
> > > >  {
> > > > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > > >  	int ret;
> > > >  	struct intel_crtc *crtc;
> > > > -	struct intel_crtc_state *new_crtc_state;
> > > > +	const struct intel_crtc_state *new_crtc_state;
> > > >  	struct intel_bw_state *new_bw_state = NULL;
> > > >  	const struct intel_bw_state *old_bw_state = NULL;
> > > >  	int i;
> > > >  
> > > >  	for_each_new_intel_crtc_in_state(state, crtc,
> > > >  					 new_crtc_state, i) {
> > > > +		bool can_sagv;
> > > > +
> > > >  		new_bw_state = intel_atomic_get_bw_state(state);
> > > >  		if (IS_ERR(new_bw_state))
> > > >  			return PTR_ERR(new_bw_state);
> > > >  
> > > >  		old_bw_state = intel_atomic_get_old_bw_state(state);
> > > >  
> > > > -		if (intel_crtc_can_enable_sagv(new_crtc_state))
> > > > +		if (INTEL_GEN(dev_priv) >= 11)
> > > > +			can_sagv = icl_crtc_can_enable_sagv(new_crtc_state);
> > > > +		else
> > > > +			can_sagv = skl_crtc_can_enable_sagv(new_crtc_state);
> > > > +
> > > > +		if (can_sagv)
> > > >  			new_bw_state->pipe_sagv_reject &= ~BIT(crtc->pipe);
> > > >  		else
> > > >  			new_bw_state->pipe_sagv_reject |= BIT(crtc->pipe);
> > > > -- 
> > > > 2.24.1.485.gad05a3d8e5
> > > 
> > > -- 
> > > Ville Syrjälä
> > > Intel
> > > _______________________________________________
> > > Intel-gfx mailing list
> > > Intel-gfx@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > 
> > -- 
> > Ville Syrjälä
> > Intel

-- 
Ville Syrjälä
Intel
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