[Intel-gfx] [PATCH v2 5/5] drm/i915/icl: Fix port B combo PHY context loss after DC transitions

[Souza, Jose]

On Tue, 2018-11-06 at 18:06 +0200, Imre Deak wrote:
> On ICL DMC/PCODE retains the HW context only for port A across DC
> transitions, for the other port B combo PHY, it doesn't. So we need
> to
> do this manually after exiting from DC6. Do the reinit even after
> exiting from DC5, it won't hurt since we only reinit the PHY in case
> it's needed (in case it was disabled to begin with).
> 
> As can be guessed from the bugzilla report leaving the PHY uninited
> will
> lead to a later timeout during the port B specific AUX and DDI_IO
> power
> well enabling.
> 
> v2:
> - Apply the fix on all GEN>=11 platforms. (Rodrigo)
> 
> Bspec: 21257
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108070
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> Cc: José Roberto de Souza <jose.souza at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_runtime_pm.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index f8da471e81aa..c20f25d6964a 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -843,6 +843,14 @@ static void gen9_dc_off_power_well_enable(struct
> drm_i915_private *dev_priv,
>  
>  	if (IS_GEN9_LP(dev_priv))
>  		bxt_verify_ddi_phy_power_wells(dev_priv);
> +
> +	if (INTEL_GEN(dev_priv) >= 11)
> +		/*
> +		 * DMC retains HW context only for port A, the other
> combo
> +		 * PHY's HW context for port B is lost after DC
> transitions,
> +		 * so we need to restore it manually.
> +		 */
> +		icl_combo_phys_init(dev_priv);
>  }
>  
>  static void gen9_dc_off_power_well_disable(struct drm_i915_private
> *dev_priv,
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