[Intel-gfx] [PATCH 2/4] drm/i915: Release DDI power well references in MST ports

[Imre Deak]

On Fri, Nov 02, 2018 at 01:39:22PM -0700, José Roberto de Souza wrote:
> MST ports did not had the post_pll_disable() hook causing the
> references get in pre_pll_enable() never being released causing
> DDI and AUX CH being enabled all the times.
> 
> Cc: Imre Deak <imre.deak at intel.com>
> Cc: Manasi Navare <manasi.d.navare at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>

Err, thanks for catching it. We really need more testing on MST.. You
could also add the Fixes: line.

> ---
>  drivers/gpu/drm/i915/intel_dp_mst.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> index 8b71d64ebd9d..8e3d0b04580b 100644
> --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> @@ -215,6 +215,20 @@ static void intel_mst_pre_pll_enable_dp(struct intel_encoder *encoder,
>  						    pipe_config, NULL);
>  }
>  
> +static void intel_mst_post_pll_disable_dp(struct intel_encoder *encoder,
> +					  const struct intel_crtc_state *pipe_config,
> +					  const struct drm_connector_state *conn_state)
> +{

Nit: these are better called old_crtc_state, old_conn_state.

> +	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
> +	struct intel_digital_port *intel_dig_port = intel_mst->primary;
> +	struct intel_dp *intel_dp = &intel_dig_port->dp;
> +
> +	if (intel_dp->active_mst_links == 0 &&
> +	    intel_dig_port->base.post_pll_disable)

Since by now all DDI platforms (which are the only platforms supporting
MST) define the .pre_pll_enable() .post_pll_disable() hooks you could
remove the NULL check for them (in a follow-up patch).

Either with or without changing the above nit:

Reviewed-by: Imre Deak <imre.deak at intel.com>

> +		intel_dig_port->base.post_pll_disable(&intel_dig_port->base,
> +						      pipe_config, NULL);
> +}
> +
>  static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
>  				    const struct intel_crtc_state *pipe_config,
>  				    const struct drm_connector_state *conn_state)
> @@ -549,6 +563,7 @@ intel_dp_create_fake_mst_encoder(struct intel_digital_port *intel_dig_port, enum
>  	intel_encoder->disable = intel_mst_disable_dp;
>  	intel_encoder->post_disable = intel_mst_post_disable_dp;
>  	intel_encoder->pre_pll_enable = intel_mst_pre_pll_enable_dp;
> +	intel_encoder->post_pll_disable = intel_mst_post_pll_disable_dp;
>  	intel_encoder->pre_enable = intel_mst_pre_enable_dp;
>  	intel_encoder->enable = intel_mst_enable_dp;
>  	intel_encoder->get_hw_state = intel_dp_mst_enc_get_hw_state;
> -- 
> 2.19.1
>