[PATCH 34/45] drm/msm/dp: add support to re-use and clear the panel edid

[Abhinav Kumar]

During certain cases, the dp mst connector's panel edid can be
re-used such as getting multiple get_modes() without irq_hpd and
should be cleared in cases when the connector is destroyed or when
irq hpd is received. Add support to handle these cases for the
mst_connector's panel edid.

Signed-off-by: Abhinav Kumar <quic_abhin...@quicinc.com>
---
 drivers/gpu/drm/msm/dp/dp_mst_drm.c | 39 +++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.c 
b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
index 
2d92084586b466d4953429e8a6fbf766d081cb9f..15c61fd37c418889074222c0f576778adadf51c9
 100644
--- a/drivers/gpu/drm/msm/dp/dp_mst_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
@@ -559,6 +559,34 @@ static struct msm_dp_mst_bridge_state 
*msm_dp_mst_br_priv_state(struct drm_atomi
                                                                                
&bridge->obj));
 }
 
+static void msm_dp_mst_clear_panel_edid(struct msm_dp *dp_display)
+{
+       struct msm_dp_mst *mst = dp_display->msm_dp_mst;
+       struct msm_dp_mst_connector *mst_conn;
+       struct msm_dp_panel *dp_panel;
+       struct msm_dp_mst_bridge *dp_bridge;
+       int i;
+
+       if (!dp_display) {
+               DRM_ERROR("invalid input\n");
+               return;
+       }
+
+       for (i = 0; i < mst->max_streams; i++) {
+               dp_bridge = &mst->mst_bridge[i];
+               mst_conn = to_msm_dp_mst_connector(dp_bridge->connector);
+               dp_panel = dp_bridge->msm_dp_panel;
+
+               if (!dp_panel || !mst_conn || !mst_conn->mst_port)
+                       continue;
+
+               if (dp_panel->drm_edid) {
+                       drm_edid_free(dp_panel->drm_edid);
+                       dp_panel->drm_edid = NULL;
+               }
+       }
+}
+
 /* DP MST HPD IRQ callback */
 void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display)
 {
@@ -585,6 +613,9 @@ void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display)
        if (handled) {
                rc = drm_dp_dpcd_writeb(mst->dp_aux, esi_res, ack[1]);
 
+               if (ack[1] & DP_UP_REQ_MSG_RDY)
+                       msm_dp_mst_clear_panel_edid(dp_display);
+
                if (rc != 1)
                        DRM_ERROR("dpcd esi_res failed. rc=%d\n", rc);
 
@@ -620,6 +651,9 @@ static int msm_dp_mst_connector_get_modes(struct 
drm_connector *connector)
        struct msm_dp_mst *mst = dp_display->msm_dp_mst;
        struct msm_dp_panel *dp_panel = mst_conn->dp_panel;
 
+       if (dp_panel->drm_edid)
+               goto duplicate_edid;
+
        drm_edid_free(dp_panel->drm_edid);
 
        dp_panel->drm_edid = drm_dp_mst_edid_read(connector, &mst->mst_mgr, 
mst_conn->mst_port);
@@ -628,6 +662,7 @@ static int msm_dp_mst_connector_get_modes(struct 
drm_connector *connector)
                return -EINVAL;
        }
 
+duplicate_edid:
        drm_edid_connector_update(connector, dp_panel->drm_edid);
 
        return drm_edid_connector_add_modes(connector);
@@ -894,6 +929,10 @@ static int msm_dp_mst_connector_atomic_check(struct 
drm_connector *connector,
 static void dp_mst_connector_destroy(struct drm_connector *connector)
 {
        struct msm_dp_mst_connector *mst_conn = 
to_msm_dp_mst_connector(connector);
+       struct msm_dp_panel *dp_panel = mst_conn->dp_panel;
+
+       drm_edid_free(dp_panel->drm_edid);
+       dp_panel->drm_edid = NULL;
 
        drm_connector_cleanup(connector);
        drm_dp_mst_put_port_malloc(mst_conn->mst_port);

-- 
2.34.1