[Intel-gfx] [PATCH 1/2] drm/i915: Use the software DRRS to select the alternative frequency for LVDS

[ykzhao]

On Thu, 2009-12-03 at 00:31 +0800, Eric Anholt wrote:
> On Thu, 5 Nov 2009 08:26:53 -0800, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> > On Thu,  5 Nov 2009 11:27:16 +0800
> > yakui.zhao at intel.com wrote:
> > 
> > > @@ -3047,20 +3047,20 @@ static int intel_crtc_mode_set(struct
> > > drm_crtc *crtc, udelay(150);
> > >  	}
> > >  
> > > +	/*
> > > +	 * According to the spec We can select between two
> > > alternative
> > > +	 * frequency by using DRRS bit only when the CxSR bit in
> > > PIPECONF
> > > +	 * register is zero. So it will clear the CxSR bit of
> > > PIPECONF
> > > +	 * register.
> > > +	 */
> > >  	if (is_lvds && has_reduced_clock && i915_powersave) {
> > >  		I915_WRITE(fp_reg + 4, fp2);
> > >  		intel_crtc->lowfreq_avail = true;
> > > -		if (HAS_PIPE_CXSR(dev)) {
> > > -			DRM_DEBUG_KMS("enabling CxSR
> > > downclocking\n");
> > > -			pipeconf |= PIPECONF_CXSR_DOWNCLOCK;
> > > -		}
> > > +		pipeconf &= ~PIPECONF_CXSR_DOWNCLOCK;
> > >  	} else {
> > >  		I915_WRITE(fp_reg + 4, fp);
> > >  		intel_crtc->lowfreq_avail = false;
> > > -		if (HAS_PIPE_CXSR(dev)) {
> > > -			DRM_DEBUG_KMS("disabling CxSR
> > > downclocking\n");
> > > -			pipeconf &= ~PIPECONF_CXSR_DOWNCLOCK;
> > > -		}
> > > +		pipeconf &= ~PIPECONF_CXSR_DOWNCLOCK;
> > >  	}
> > >  
> > >  	I915_WRITE(htot_reg, (adjusted_mode->crtc_hdisplay - 1) |
> > > @@ -3750,7 +3750,7 @@ static void intel_increase_pllclock(struct
> > > drm_crtc *crtc, bool schedule) if (!dev_priv->lvds_downclock_avail)
> > >  		return;
> > >  
> > > -	if (!HAS_PIPE_CXSR(dev) && (dpll &
> > > DISPLAY_RATE_SELECT_FPA1)) {
> > > +	if (HAS_PIPE_CXSR(dev) && (dpll & DISPLAY_RATE_SELECT_FPA1))
> > > { DRM_DEBUG_DRIVER("upclocking LVDS\n");
> > 
> > Don't we want to use the automatic C-state based downclock if
> > possible?  That's the idea behind the manual clocking (in
> > increase/decrease_pllclock) and the automatic clocking bit in the
> > pipeconf register at least.  Did you test that and find it to be buggy
> > or something?
> 
> Any response?

Hi, Eric
   Please ignore this patch as it is out of date.
  
   The hardware DRRS can select the alternative frequency for LVDS on
g4x platform. So it is unnecessary to change it to software DRRS.
   
thanks.
	Yakui