[Intel-gfx] [PATCH 08/10] drm/i915/skl: disable DC states before display core init/uninit

[Patrik Jakobsson]

On Wed, Nov 04, 2015 at 07:24:17PM +0200, Imre Deak wrote:
> We need to disable the DC states during display core init to sanitize
> the HW state we inherit from the BIOS. We need to disable it during
> display core uninit too, since the power well framework will leave it
> enabled (since we get to the display core uninit step with all power
> domains disabled already).
> 
> Signed-off-by: Imre Deak <imre.deak at intel.com>

Reviewed-by: Patrik Jakobsson <patrik.jakobsson at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_runtime_pm.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index f5fb003..3d500e1d 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -1900,6 +1900,8 @@ static void skl_display_core_init(struct drm_i915_private *dev_priv,
>  	struct i915_power_domains *power_domains = &dev_priv->power_domains;
>  	uint32_t val;
>  
> +	gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
> +
>  	/* enable PCH reset handshake */
>  	val = I915_READ(HSW_NDE_RSTWRN_OPT);
>  	I915_WRITE(HSW_NDE_RSTWRN_OPT, val | RESET_PCH_HANDSHAKE_ENABLE);
> @@ -1921,6 +1923,8 @@ static void skl_display_core_uninit(struct drm_i915_private *dev_priv)
>  {
>  	struct i915_power_domains *power_domains = &dev_priv->power_domains;
>  
> +	gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
> +
>  	skl_uninit_cdclk(dev_priv);
>  
>  	/* The spec doesn't call for removing the reset handshake flag */
> -- 
> 2.1.4
>