On Tue, Oct 24, 2023 at 04:09:22AM +0300, Imre Deak wrote:
> Enabling / disabling DSC decompression in the branch device downstream
> of the source may reset the while branch device. To avoid this while the
"may reset the whOle branch device" I guess?
> streams are still active, force a modeset on all CRTC/ports connected to
> this branch device.
>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 4 ++
> drivers/gpu/drm/i915/display/intel_dp_mst.c | 72 ++++++++++++++++++++
> drivers/gpu/drm/i915/display/intel_dp_mst.h | 2 +
> 3 files changed, 78 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 22f88389035bd..a33e5bbf5165a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6490,6 +6490,10 @@ int intel_atomic_check(struct drm_device *dev,
> if (!new_crtc_state->hw.enable || intel_crtc_needs_modeset(new_crtc_state))
> continue;
>
> + if (intel_dp_mst_crtc_needs_modeset(state, crtc))
> + intel_modeset_pipes_in_mask_early(state, "MST topology",
> + BIT(crtc->pipe));
> +
> if (intel_dp_mst_is_slave_trans(new_crtc_state)) {
> enum transcoder master = new_crtc_state->mst_master_transcoder;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 9f4894c2e7860..d4dcfb2c09b2a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -1606,3 +1606,75 @@ int intel_dp_mst_add_topology_state_for_crtc(struct intel_atomic_state *state,
>
> return 0;
> }
> +
> +static struct intel_connector *
> +get_connector_in_state_for_crtc(struct intel_atomic_state *state,
> + const struct intel_crtc *crtc)
> +{
> + struct drm_connector_state *old_conn_state;
> + struct drm_connector_state *new_conn_state;
> + struct drm_connector *_connector;
> + int i;
> +
> + for_each_oldnew_connector_in_state(&state->base, _connector,
> + old_conn_state, new_conn_state, i) {
> + struct intel_connector *connector =
> + to_intel_connector(_connector);
> +
> + if (old_conn_state->crtc == &crtc->base ||
> + new_conn_state->crtc == &crtc->base)
> + return connector;
> + }
> +
> + return NULL;
> +}
> +
> +bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,
> + struct intel_crtc *crtc)
> +{
> + const struct intel_connector *crtc_connector;
> + const struct drm_connector_state *conn_state;
> + const struct drm_connector *_connector;
> + int i;
> +
> + if (!intel_crtc_has_type(intel_atomic_get_new_crtc_state(state, crtc),
> + INTEL_OUTPUT_DP_MST))
> + return false;
> +
> + crtc_connector = get_connector_in_state_for_crtc(state, crtc);
> +
> + if (!crtc_connector)
> + /* None of the connectors in the topology needs modeset */
> + return false;
> +
> + for_each_new_connector_in_state(&state->base, _connector, conn_state, i) {
> + const struct intel_connector *connector =
> + to_intel_connector(_connector);
> + const struct intel_crtc_state *new_crtc_state =
> + intel_atomic_get_new_crtc_state(state, crtc);
> + const struct intel_crtc_state *old_crtc_state =
> + intel_atomic_get_old_crtc_state(state, crtc);
> +
> + if (connector->mst_port != crtc_connector->mst_port)
> + continue;
> +
> + if (!intel_crtc_needs_modeset(new_crtc_state))
> + continue;
> +
> + if (old_crtc_state->dsc.compression_enable ==
> + new_crtc_state->dsc.compression_enable)
> + continue;
> +
> + /*
> + * Toggling the compression flag because of this stream in the first
> + * downstream branch device's UFP DPCD may reset the whole branch
> + * device. To avoid the reset while other streams are also
> + * active modeset the whole MST topology in this case.
> + */
> + if (connector->dp.dsc_decompression_aux ==
> + &connector->mst_port->aux)
> + return true;
> + }
> +
> + return false;
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> index f1815bb722672..fc5e85776a858 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> @@ -22,5 +22,7 @@ bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state);
> bool intel_dp_mst_source_support(struct intel_dp *intel_dp);
> int intel_dp_mst_add_topology_state_for_crtc(struct intel_atomic_state *state,
> struct intel_crtc *crtc);
> +bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,
> + struct intel_crtc *crtc);
>
> #endif /* __INTEL_DP_MST_H__ */
> --
> 2.39.2
>
