From f2c18c0fcda121877ec8a90a6105ee8fe203b782 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Date: Tue, 26 May 2020 04:14:43 +0300
Subject: drm: bridge: Return NULL on error from drm_bridge_get_edid()
Git-commit: 11d3cf804591246bb5e09cb03cb30121eafc2f4c
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

The drm_bridge_get_edid() function is documented to return an error
pointer on error. The underlying .get_edid() operation, however, returns
NULL on error, and so do the drm_get_edid() and drm_do_get_edid()
functions upon which .get_edid() is usually implemented. Make
drm_bridge_get_edid() return NULL on error to be consistent.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200526011505.31884-6-laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/bridge/ti-tfp410.c | 10 +++++++---
 drivers/gpu/drm/drm_bridge.c       |  6 +++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
index 21d99b4ea0c9..6467e6f2f1fa 100644
--- a/drivers/gpu/drm/bridge/ti-tfp410.c
+++ b/drivers/gpu/drm/bridge/ti-tfp410.c
@@ -51,11 +51,15 @@ static int tfp410_get_modes(struct drm_connector *connector)
 	struct edid *edid;
 	int ret;
 
-	edid = drm_bridge_get_edid(dvi->next_bridge, connector);
-	if (IS_ERR_OR_NULL(edid)) {
-		if (edid != ERR_PTR(-ENOTSUPP))
+	if (dvi->next_bridge->ops & DRM_BRIDGE_OP_EDID) {
+		edid = drm_bridge_get_edid(dvi->next_bridge, connector);
+		if (!edid)
 			DRM_INFO("EDID read failed. Fallback to standard modes\n");
+	} else {
+		edid = NULL;
+	}
 
+	if (!edid) {
 		/*
 		 * No EDID, fallback on the XGA standard modes and prefer a mode
 		 * pretty much anything can handle.
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index afdec8e5fc68..fe1e3460b486 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -1086,16 +1086,16 @@ EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
  *
  * If the bridge supports output EDID retrieval, as reported by the
  * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
- * get the EDID and return it. Otherwise return ERR_PTR(-ENOTSUPP).
+ * get the EDID and return it. Otherwise return NULL.
  *
  * RETURNS:
- * The retrieved EDID on success, or an error pointer otherwise.
+ * The retrieved EDID on success, or NULL otherwise.
  */
 struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
 				 struct drm_connector *connector)
 {
 	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
-		return ERR_PTR(-ENOTSUPP);
+		return NULL;
 
 	return bridge->funcs->get_edid(bridge, connector);
 }
-- 
2.29.2