From c9ac9762cc888df4b90d74b6b3c925976c5b5cd1 Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Thu, 30 Apr 2020 12:24:05 -0400
Subject: drm/amd/display: Don't pass invalid fw_bss_data pointer into DMUB srv
Git-commit: 0922b899f36621126d49c0d86e90fb18d572d8a1
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

[Why]
If bss_data_size is 0 then we shouldn't be passing down fw_bss_data into
the DMUB service since the region isn't really "valid."

[How]
Pass NULL instead if the size is 0.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Zhan Liu <Zhan.Liu@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 710edc70e37e..60ef6f559720 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1237,10 +1237,10 @@ static int dm_dmub_sw_init(struct amdgpu_device *adev)
 					PSP_HEADER_BYTES - PSP_FOOTER_BYTES;
 	region_params.bss_data_size = le32_to_cpu(hdr->bss_data_bytes);
 	region_params.vbios_size = adev->bios_size;
-	region_params.fw_bss_data =
+	region_params.fw_bss_data = region_params.bss_data_size ?
 		adev->dm.dmub_fw->data +
 		le32_to_cpu(hdr->header.ucode_array_offset_bytes) +
-		le32_to_cpu(hdr->inst_const_bytes);
+		le32_to_cpu(hdr->inst_const_bytes) : NULL;
 	region_params.fw_inst_const =
 		adev->dm.dmub_fw->data +
 		le32_to_cpu(hdr->header.ucode_array_offset_bytes) +
-- 
2.29.2