diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
index 0e81e03e9b498762febe0787028bf22e31d1d3d6..0fe714f54cca9b1e38d6d536cde126001ce5ecc4 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
@@ -841,12 +841,12 @@ static int gmc_v6_0_sw_init(void *handle)
 
 	adev->gmc.mc_mask = 0xffffffffffULL;
 
-	r = dma_set_mask_and_coherent(adev->dev, DMA_BIT_MASK(44));
+	r = dma_set_mask_and_coherent(adev->dev, DMA_BIT_MASK(40));
 	if (r) {
 		dev_warn(adev->dev, "No suitable DMA available.\n");
 		return r;
 	}
-	adev->need_swiotlb = drm_need_swiotlb(44);
+	adev->need_swiotlb = drm_need_swiotlb(40);
 
 	r = gmc_v6_0_init_microcode(adev);
 	if (r) {