[Intel-gfx] [PATCH] drm/i915/skl: Init cdclk in the driver rather than relying on pre-os

[Imre Deak]

On ma, 2015-10-05 at 20:52 +0530, Shobhit Kumar wrote:
> Mostly reuse what is programmed by pre-os, but in case there is no
> pre-os initialization, init the cdclk with the default value.
> 
> Cc: Imre Deak <imre.deak at intel.com>
> Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_ddi.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 2d3cc82..675c60d 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -2947,10 +2947,8 @@ 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");
> -		else
> -			intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
> +
> +		skl_init_cdclk(dev_priv);

How does this prevent changing the clock if BIOS did enable some output?
We shouldn't change the clock in that case.

>  	} else if (IS_BROXTON(dev)) {
>  		broxton_init_cdclk(dev);
>  		broxton_ddi_phy_init(dev);