drm/mediatek: use correct device to import PRIME buffers

PRIME buffers should be imported using the DMA device. To this end, use
a custom import function that mimics drm_gem_prime_import_dev(), but
passes the correct device.

Fixes: 119f5173 ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_drv.c

@@ -320,6 +320,18 @@ static const struct file_operations mtk_drm_fops = {
 	.compat_ioctl = drm_compat_ioctl,
 };
 
+/*
+ * We need to override this because the device used to import the memory is
+ * not dev->dev, as drm_gem_prime_import() expects.
+ */
+struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
+						struct dma_buf *dma_buf)
+{
+	struct mtk_drm_private *private = dev->dev_private;
+
+	return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
+}
+
 static struct drm_driver mtk_drm_driver = {
 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
 			   DRIVER_ATOMIC,
@@ -331,7 +343,7 @@ static struct drm_driver mtk_drm_driver = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_export = drm_gem_prime_export,
-	.gem_prime_import = drm_gem_prime_import,
+	.gem_prime_import = mtk_drm_gem_prime_import,
 	.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
 	.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
 	.gem_prime_mmap = mtk_drm_gem_mmap_buf,