1 files changed, 25 insertions, 8 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
index 274909271c36..613bf8a5d9b2 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -25,6 +25,7 @@
 
 #include "drmP.h"
 #include "drm.h"
+#include "exynos_drm.h"
 #include "exynos_drm_drv.h"
 #include "exynos_drm_gem.h"
 
@@ -86,6 +87,10 @@ static struct sg_table *
 	npages = buf->size / buf->page_size;
 
 	sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
+	if (!sgt) {
+		DRM_DEBUG_PRIME("exynos_pages_to_sg returned NULL!\n");
+		goto err_unlock;
+	}
 	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
 
 	DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
@@ -186,7 +191,7 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 	struct exynos_drm_gem_obj *exynos_gem_obj;
 	struct exynos_drm_gem_buf *buffer;
 	struct page *page;
-	int ret, i = 0;
+	int ret;
 
 	DRM_DEBUG_PRIME("%s\n", __FILE__);
 
@@ -210,7 +215,7 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 
 
 	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
-	if (IS_ERR(sgt)) {
+	if (IS_ERR_OR_NULL(sgt)) {
 		ret = PTR_ERR(sgt);
 		goto err_buf_detach;
 	}
@@ -236,13 +241,25 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 	}
 
 	sgl = sgt->sgl;
-	buffer->dma_addr = sg_dma_address(sgl);
 
-	while (i < sgt->nents) {
-		buffer->pages[i] = sg_page(sgl);
-		buffer->size += sg_dma_len(sgl);
-		sgl = sg_next(sgl);
-		i++;
+	if (sgt->nents == 1) {
+		buffer->dma_addr = sg_dma_address(sgt->sgl);
+		buffer->size = sg_dma_len(sgt->sgl);
+
+		/* always physically continuous memory if sgt->nents is 1. */
+		exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
+	} else {
+		unsigned int i = 0;
+
+		buffer->dma_addr = sg_dma_address(sgl);
+		while (i < sgt->nents) {
+			buffer->pages[i] = sg_page(sgl);
+			buffer->size += sg_dma_len(sgl);
+			sgl = sg_next(sgl);
+			i++;
+		}
+
+		exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
 	}
 
 	exynos_gem_obj->buffer = buffer;