On Thu, 07 Nov 2024, Jani Nikula <jani.nikula@xxxxxxxxx> wrote:
> It would be best to have self-explanatory code, but lacking that, add
> some comments about the way the DDI encoder hooks get called from DP MST
> stream encoders.
The subject prefix should be "drm/i915/ddi:".
>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 51 ++++++++++++++++++------
> 1 file changed, 38 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index c973b70185cf..9965d7603d6c 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2920,6 +2920,24 @@ static void intel_ddi_pre_enable_hdmi(struct intel_atomic_state *state,
> crtc_state, conn_state);
> }
>
> +/*
> + * Note: Also called from the ->pre_enable of the first active MST stream
> + * encoder on its primary encoder.
> + *
> + * When called from DP MST code:
> + *
> + * - conn_state will be NULL
> + *
> + * - encoder will be the primary encoder (i.e. mst->primary)
> + *
> + * - the main connector associated with this port won't be active or linked to a
> + * crtc
> + *
> + * - crtc_state will be the state of the first stream to be activated on this
> + * port, and it may not be the same stream that will be deactivated last, but
> + * each stream should have a state that is identical when it comes to the DP
> + * link parameteres
> + */
> static void intel_ddi_pre_enable(struct intel_atomic_state *state,
> struct intel_encoder *encoder,
> const struct intel_crtc_state *crtc_state,
> @@ -2929,19 +2947,6 @@ static void intel_ddi_pre_enable(struct intel_atomic_state *state,
> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> enum pipe pipe = crtc->pipe;
>
> - /*
> - * When called from DP MST code:
> - * - conn_state will be NULL
> - * - encoder will be the main encoder (ie. mst->primary)
> - * - the main connector associated with this port
> - * won't be active or linked to a crtc
> - * - crtc_state will be the state of the first stream to
> - * be activated on this port, and it may not be the same
> - * stream that will be deactivated last, but each stream
> - * should have a state that is identical when it comes to
> - * the DP link parameteres
> - */
> -
> drm_WARN_ON(&dev_priv->drm, crtc_state->has_pch_encoder);
>
> intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true);
> @@ -3191,6 +3196,11 @@ static void intel_ddi_post_disable_hdmi_or_sst(struct intel_atomic_state *state,
> }
> }
>
> +/*
> + * Note: Also called from the ->post_disable of the last active MST stream
> + * encoder on its primary encoder. See also the comment for
> + * intel_ddi_pre_enable().
> + */
> static void intel_ddi_post_disable(struct intel_atomic_state *state,
> struct intel_encoder *encoder,
> const struct intel_crtc_state *old_crtc_state,
> @@ -3221,6 +3231,11 @@ static void intel_ddi_post_disable(struct intel_atomic_state *state,
> old_conn_state);
> }
>
> +/*
> + * Note: Also called from the ->post_pll_disable of the last active MST stream
> + * encoder on its primary encoder. See also the comment for
> + * intel_ddi_pre_enable().
> + */
> static void intel_ddi_post_pll_disable(struct intel_atomic_state *state,
> struct intel_encoder *encoder,
> const struct intel_crtc_state *old_crtc_state,
> @@ -3558,6 +3573,11 @@ void intel_ddi_update_active_dpll(struct intel_atomic_state *state,
> intel_update_active_dpll(state, pipe_crtc, encoder);
> }
>
> +/*
> + * Note: Also called from the ->pre_pll_enable of the first active MST stream
> + * encoder on its primary encoder. See also the comment for
> + * intel_ddi_pre_enable().
> + */
> static void
> intel_ddi_pre_pll_enable(struct intel_atomic_state *state,
> struct intel_encoder *encoder,
> @@ -3996,6 +4016,11 @@ static void intel_ddi_read_func_ctl(struct intel_encoder *encoder,
> }
> }
>
> +/*
> + * Note: Also called from the ->get_config of the MST stream encoders on their
> + * primary encoder, via the platform specific hooks here. See also the comment
> + * for intel_ddi_pre_enable().
> + */
> static void intel_ddi_get_config(struct intel_encoder *encoder,
> struct intel_crtc_state *pipe_config)
> {
--
Jani Nikula, Intel
