drm/amd/display: Check DMCU Exists Before Loading

BugLink: https://bugs.launchpad.net/bugs/1889669
[ Upstream commit 17bdb4a82fe5014c8aa5b2103c80c5729744a096 ]

Signed-off-by: Jerry (Fangzhi) Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

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 4fad0b603b3abdc601a0ef1d1bac7e98d65dc6a4..c7d8edf450d3cc27e6eb3555239fbbdd304b9637 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -928,9 +928,14 @@ static int dm_late_init(void *handle)
        struct dmcu_iram_parameters params;
        unsigned int linear_lut[16];
        int i;
-       struct dmcu *dmcu = adev->dm.dc->res_pool->dmcu;
+       struct dmcu *dmcu = NULL;
        bool ret;
 
+       if (!adev->dm.fw_dmcu)
+               return detect_mst_link_for_all_connectors(adev->ddev);
+
+       dmcu = adev->dm.dc->res_pool->dmcu;
+
        for (i = 0; i < 16; i++)
                linear_lut[i] = 0xFFFF * i / 15;