drm/v3d/v3d_drv: Check for error num after setting mask

Because of the possible failure of the dma_supported(), the
dma_set_mask_and_coherent() may return error num.
Therefore, it should be better to check it and return the error if
fails.
Also, we can create a variable for the mask to solve the
alignment issue.

Fixes: 334dd38a ("drm/v3d: Set dma_mask as well as coherent_dma_mask")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220110013807.4105270-1-jiasheng@iscas.ac.cn

drivers/gpu/drm/v3d/v3d_drv.c

@@ -219,6 +219,7 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 	int ret;
 	u32 mmu_debug;
 	u32 ident1;
+	u64 mask;
 
 	v3d = devm_drm_dev_alloc(dev, &v3d_drm_driver, struct v3d_dev, drm);
 	if (IS_ERR(v3d))
@@ -237,8 +238,11 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 		return ret;
 
 	mmu_debug = V3D_READ(V3D_MMU_DEBUG_INFO);
-	dma_set_mask_and_coherent(dev,
-		DMA_BIT_MASK(30 + V3D_GET_FIELD(mmu_debug, V3D_MMU_PA_WIDTH)));
+	mask = DMA_BIT_MASK(30 + V3D_GET_FIELD(mmu_debug, V3D_MMU_PA_WIDTH));
+	ret = dma_set_mask_and_coherent(dev, mask);
+	if (ret)
+		return ret;
+
 	v3d->va_width = 30 + V3D_GET_FIELD(mmu_debug, V3D_MMU_VA_WIDTH);
 
 	ident1 = V3D_READ(V3D_HUB_IDENT1);