drm/bridge: cadence: cdns-mhdp8546-core: Handle HDCP state in bridge atomic check

[ Upstream commit 4a8edd6 ]

Now that we have DRM_BRIDGE_ATTACH_NO_CONNECTOR framework, handle the
HDCP state change in bridge atomic check as well to enable correct
functioning for HDCP in both DRM_BRIDGE_ATTACH_NO_CONNECTOR and
!DRM_BRIDGE_ATTACH_NO_CONNECTOR case.

Without this patch, when using DRM_BRIDGE_ATTACH_NO_CONNECTOR flag, HDCP
state changes would not be properly handled during atomic commits,
potentially leading to HDCP authentication failures or incorrect
protection status for content requiring HDCP encryption.

Fixes: 6a3608e ("drm: bridge: cdns-mhdp8546: Enable HDCP")
Signed-off-by: Harikrishna Shenoy <h-shenoy@ti.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patch.msgid.link/20251209120332.3559893-4-h-shenoy@ti.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: h-shenoy

drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c

@@ -2196,6 +2196,10 @@ static int cdns_mhdp_atomic_check(struct drm_bridge *bridge,
 {
 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
 	const struct drm_display_mode *mode = &crtc_state->adjusted_mode;
+	struct drm_connector_state *old_state, *new_state;
+	struct drm_atomic_state *state = crtc_state->state;
+	struct drm_connector *conn = mhdp->connector_ptr;
+	u64 old_cp, new_cp;
 
 	mutex_lock(&mhdp->link_mutex);
 
@@ -2215,6 +2219,25 @@ static int cdns_mhdp_atomic_check(struct drm_bridge *bridge,
 	if (mhdp->info)
 		bridge_state->input_bus_cfg.flags = *mhdp->info->input_bus_flags;
 
+	if (conn && mhdp->hdcp_supported) {
+		old_state = drm_atomic_get_old_connector_state(state, conn);
+		new_state = drm_atomic_get_new_connector_state(state, conn);
+		old_cp = old_state->content_protection;
+		new_cp = new_state->content_protection;
+
+		if (old_state->hdcp_content_type != new_state->hdcp_content_type &&
+		    new_cp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
+			new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+			crtc_state = drm_atomic_get_new_crtc_state(state, new_state->crtc);
+			crtc_state->mode_changed = true;
+		}
+
+		if (!new_state->crtc) {
+			if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+				new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		}
+	}
+
 	mutex_unlock(&mhdp->link_mutex);
 	return 0;
 }