[Intel-gfx] [v4] drm/i915/skl: If needed sanitize bios programmed cdclk

[Daniel Vetter]

On Tue, Oct 20, 2015 at 03:52:10PM +0300, Ville Syrjälä wrote:
> On Tue, Oct 20, 2015 at 06:13:12PM +0530, Shobhit Kumar wrote:
> > Especially in cases where pre-os does not enable display, cdclk might
> > not be in sane state. During sanitization initialize cdclk with maximum
> > value till we get dynamic cdclk support.
> > 
> > v2: Check if BIOS programmed correctly rather than always calling init
> >     - Do validation of programmed cdctl and what it is expected
> >     - Only do slk_init_cdclk if validation failed else reuse BIOS
> >       programmed value
> > 
> > v3: Move the validation logic in a separate sanitize function (Ville)
> > 
> > v4: No need to check LCPLL after sanitize and use max_cdclk_freq instead
> >     of hardcoded value (Ville)
> > 
> > Cc: Imre Deak <imre.deak at intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Queued for -next, thanks for the patch.
-Daniel

> 
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c     |  4 ++--
> >  drivers/gpu/drm/i915/intel_display.c | 31 +++++++++++++++++++++++++++++++
> >  drivers/gpu/drm/i915/intel_drv.h     |  1 +
> >  3 files changed, 34 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > index b25e99a..824b863 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -2949,8 +2949,8 @@ void intel_ddi_pll_init(struct drm_device *dev)
> >  
> >  		cdclk_freq = dev_priv->display.get_display_clock_speed(dev);
> >  		dev_priv->skl_boot_cdclk = cdclk_freq;
> > -		if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
> > -			DRM_ERROR("LCPLL1 is disabled\n");
> > +		if (skl_sanitize_cdclk(dev_priv))
> > +			DRM_DEBUG_KMS("Sanitized cdclk programmed by pre-os\n");
> >  		else
> >  			intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
> >  	} else if (IS_BROXTON(dev)) {
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 5f37f84..4933b72 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -5784,6 +5784,37 @@ void skl_init_cdclk(struct drm_i915_private *dev_priv)
> >  		DRM_ERROR("DBuf power enable timeout\n");
> >  }
> >  
> > +int skl_sanitize_cdclk(struct drm_i915_private *dev_priv)
> > +{
> > +	uint32_t lcpll1 = I915_READ(LCPLL1_CTL);
> > +	uint32_t cdctl = I915_READ(CDCLK_CTL);
> > +	int freq = dev_priv->skl_boot_cdclk;
> > +
> > +	/* Is PLL enabled and locked ? */
> > +	if (!((lcpll1 & LCPLL_PLL_ENABLE) && (lcpll1 & LCPLL_PLL_LOCK)))
> > +		goto sanitize;
> > +
> > +	/* DPLL okay; verify the cdclock
> > +	 *
> > +	 * Noticed in some instances that the freq selection is correct but
> > +	 * decimal part is programmed wrong from BIOS where pre-os does not
> > +	 * enable display. Verify the same as well.
> > +	 */
> > +	if (cdctl == ((cdctl & CDCLK_FREQ_SEL_MASK) | skl_cdclk_decimal(freq)))
> > +		/* All well; nothing to sanitize */
> > +		return false;
> > +sanitize:
> > +	/*
> > +	 * As of now initialize with max cdclk till
> > +	 * we get dynamic cdclk support
> > +	 * */
> > +	dev_priv->skl_boot_cdclk = dev_priv->max_cdclk_freq;
> > +	skl_init_cdclk(dev_priv);
> > +
> > +	/* we did have to sanitize */
> > +	return true;
> > +}
> > +
> >  /* Adjust CDclk dividers to allow high res or save power if possible */
> >  static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
> >  {
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 0598932..ec10e6a 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1152,6 +1152,7 @@ void broxton_ddi_phy_uninit(struct drm_device *dev);
> >  void bxt_enable_dc9(struct drm_i915_private *dev_priv);
> >  void bxt_disable_dc9(struct drm_i915_private *dev_priv);
> >  void skl_init_cdclk(struct drm_i915_private *dev_priv);
> > +int skl_sanitize_cdclk(struct drm_i915_private *dev_priv);
> >  void skl_uninit_cdclk(struct drm_i915_private *dev_priv);
> >  void intel_dp_get_m_n(struct intel_crtc *crtc,
> >  		      struct intel_crtc_state *pipe_config);
> > -- 
> > 2.4.3
> 
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch