drm/amd/amdgpu: Correct VRAM width for APUs with GMC9

DDR4 has a 64-bit width not 128-bits.  It was reporting
twice the width.  Tested with my Ryzen 2400G.

Signed-off-by: Tom St Denis <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index bc4bd5e7ac9424012e6f48ed8d86bb0978b3f16c..4dd469188e2b46b6b6d5a3e025153592f2aa5b4e 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -722,7 +722,10 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
                adev->gmc.vram_width = amdgpu_atomfirmware_get_vram_width(adev);
        if (!adev->gmc.vram_width) {
                /* hbm memory channel size */
-               chansize = 128;
+               if (adev->flags & AMD_IS_APU)
+                       chansize = 64;
+               else
+                       chansize = 128;
 
                tmp = RREG32_SOC15(DF, 0, mmDF_CS_AON0_DramBaseAddress0);
                tmp &= DF_CS_AON0_DramBaseAddress0__IntLvNumChan_MASK;