drm/amdgpu: Read vram width from integrated system info table
On KB, KV, CZ we should read the vram width from integrated system
table, if we can. The NOOFCHAN in MC_SHARED_CHMAP is not accurate.
With this change we can enable two 4k displays on CZ again. This use
case was broken sometime in January when we started looking at
vram_width for bandwidth calculations instead of hardcoding this value.
v2:
Return 0 if integrated system info table is not available.
Tested-by: Roman Li <roman.li@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
index 4e0f488..38d0fe3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h
@@ -148,6 +148,8 @@ int amdgpu_atombios_get_clock_info(struct amdgpu_device *adev);
int amdgpu_atombios_get_gfx_info(struct amdgpu_device *adev);
+int amdgpu_atombios_get_vram_width(struct amdgpu_device *adev);
+
bool amdgpu_atombios_get_asic_ss_info(struct amdgpu_device *adev,
struct amdgpu_atom_ss *ss,
int id, u32 clock);