From: jsg <jsg@openbsd.org>
Date: Thu, 23 Feb 2023 02:24:10 +0000 (+0000)
Subject: drm/amd/display: Properly handle additional cases where DCN is not supported
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=91354d167aa9c40abb01ec37b3075692d767e95d;p=openbsd

drm/amd/display: Properly handle additional cases where DCN is not supported

From Alex Deucher
b4e79d0c7f9bb938525716b3e05cfca6418e2bae in linux-6.1.y/6.1.13
6fc547a5a2ef5ce05b16924106663ab92f8f87a7 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index e1c98e9a53c..4f4ff3180c6 100644
--- a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4528,6 +4528,17 @@ DEVICE_ATTR_WO(s3_debug);
 static int dm_early_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+	struct amdgpu_mode_info *mode_info = &adev->mode_info;
+	struct atom_context *ctx = mode_info->atom_context;
+	int index = GetIndexIntoMasterTable(DATA, Object_Header);
+	u16 data_offset;
+
+	/* if there is no object header, skip DM */
+	if (!amdgpu_atom_parse_data_header(ctx, index, NULL, NULL, NULL, &data_offset)) {
+		adev->harvest_ip_mask |= AMD_HARVEST_IP_DMU_MASK;
+		dev_info(adev->dev, "No object header, skipping DM\n");
+		return -ENOENT;
+	}
 
 	switch (adev->asic_type) {
 #if defined(CONFIG_DRM_AMD_DC_SI)