Re: [PATCH] drm/i915: simplify intel_ddi_pll_select()

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

On Wed, Mar 22, 2017 at 02:40:01PM -0300, Paulo Zanoni wrote:
> Em Qua, 2017-03-22 às 15:21 +0200, Ville Syrjälä escreveu:
> > On Tue, Mar 21, 2017 at 06:57:10PM -0300, Paulo Zanoni wrote:
> > > 
> > > Because {hsw,skl,bxt}_ddi_pll_select all pretty much do the same
> > > thing
> > > in slightly different ways. Replace everything with a simple copy
> > > of
> > > the function and inline it inside intle_ddi_pll_select().
> > > 
> > > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/intel_ddi.c | 58 +++++-----------------------
> > > ------------
> > >  1 file changed, 7 insertions(+), 51 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > > b/drivers/gpu/drm/i915/intel_ddi.c
> > > index d8214ba..bd6fd0b 100644
> > > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > > @@ -1127,47 +1127,6 @@ void intel_ddi_clock_get(struct
> > > intel_encoder *encoder,
> > >  		bxt_ddi_clock_get(encoder, pipe_config);
> > >  }
> > >  
> > > -static bool
> > > -hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
> > > -		   struct intel_crtc_state *crtc_state,
> > > -		   struct intel_encoder *encoder)
> > > -{
> > > -	struct intel_shared_dpll *pll;
> > > -
> > > -	pll = intel_get_shared_dpll(intel_crtc, crtc_state,
> > > -				    encoder);
> > > -	if (!pll)
> > > -		DRM_DEBUG_DRIVER("failed to find PLL for pipe
> > > %c\n",
> > > -				 pipe_name(intel_crtc->pipe));
> > > -
> > > -	return pll;
> > > -}
> > > -
> > > -static bool
> > > -skl_ddi_pll_select(struct intel_crtc *intel_crtc,
> > > -		   struct intel_crtc_state *crtc_state,
> > > -		   struct intel_encoder *encoder)
> > > -{
> > > -	struct intel_shared_dpll *pll;
> > > -
> > > -	pll = intel_get_shared_dpll(intel_crtc, crtc_state,
> > > encoder);
> > > -	if (pll == NULL) {
> > > -		DRM_DEBUG_DRIVER("failed to find PLL for pipe
> > > %c\n",
> > > -				 pipe_name(intel_crtc->pipe));
> > > -		return false;
> > > -	}
> > > -
> > > -	return true;
> > > -}
> > > -
> > > -static bool
> > > -bxt_ddi_pll_select(struct intel_crtc *intel_crtc,
> > > -		   struct intel_crtc_state *crtc_state,
> > > -		   struct intel_encoder *encoder)
> > > -{
> > > -	return !!intel_get_shared_dpll(intel_crtc, crtc_state,
> > > encoder);
> > > -}
> > > -
> > >  /*
> > >   * Tries to find a *shared* PLL for the CRTC and store it in
> > >   * intel_crtc->ddi_pll_sel.
> > > @@ -1178,19 +1137,16 @@ bxt_ddi_pll_select(struct intel_crtc
> > > *intel_crtc,
> > >  bool intel_ddi_pll_select(struct intel_crtc *intel_crtc,
> > >  			  struct intel_crtc_state *crtc_state)
> > >  {
> > > -	struct drm_i915_private *dev_priv = to_i915(intel_crtc-
> > > >base.dev);
> > >  	struct intel_encoder *encoder =
> > >  		intel_ddi_get_crtc_new_encoder(crtc_state);
> > > +	struct intel_shared_dpll *pll;
> > >  
> > > -	if (IS_GEN9_BC(dev_priv))
> > > -		return skl_ddi_pll_select(intel_crtc, crtc_state,
> > > -					  encoder);
> > > -	else if (IS_GEN9_LP(dev_priv))
> > > -		return bxt_ddi_pll_select(intel_crtc, crtc_state,
> > > -					  encoder);
> > > -	else
> > > -		return hsw_ddi_pll_select(intel_crtc, crtc_state,
> > > -					  encoder);
> > > +	pll = intel_get_shared_dpll(intel_crtc, crtc_state,
> > > encoder);
> > 
> > I wonder if intel_ddi_pll_select() has any good reason to even exist
> > anymore. It's just calling this one function, so maybe we should just
> > call it directly?
> 
> You're right here. Then the two callers would be
> haswell_crtc_compute_clock() and ironlake_crtc_compute_clock(), which
> makes even more sene. I'll submit another patch.
> 
> > 
> > > 
> > > +	if (!pll)
> > > +		DRM_DEBUG_DRIVER("failed to find PLL for pipe
> > > %c\n",
> > > +				  pipe_name(intel_crtc->pipe));
> > > +
> > > +	return pll;
> > 
> > I would probably write 'pll != NULL' for a bit of extra clarity.
> 
> Are you talking about the return statement or the if condition?

The return.

> 
> I'll assume you're talking about the return statement. I can fix this.
> Another thing would be "return !!pll". I'm fine with all approaches.

For whatever reason I've started to prefer !=NULL type of stuff.
Not really sure why since I used to dislike it when I was younger.

> 
> > 
> > Either way
> > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Thanks!
> 
> > 
> > > 
> > >  }
> > >  
> > >  void intel_ddi_set_pipe_settings(const struct intel_crtc_state
> > > *crtc_state)
> > > -- 
> > > 2.7.4
> > > 
> > > _______________________________________________
> > > Intel-gfx mailing list
> > > Intel-gfx@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > 

-- 
Ville Syrjälä
Intel OTC
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx