[PATCH 1/2] drm/udl: handle page mapping in dmabuf export.

[Haixia Shi]

Fixes dmabuf export failure with -E_NOMEM when the page is not mapped.

Signed-off-by: Haixia Shi <hshi at chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>
---
 drivers/gpu/drm/udl/udl_dmabuf.c | 7 +++++--
 drivers/gpu/drm/udl/udl_drv.h    | 2 ++
 drivers/gpu/drm/udl/udl_gem.c    | 4 ++--
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/udl/udl_dmabuf.c b/drivers/gpu/drm/udl/udl_dmabuf.c
index 1d85c3a..2425b76 100644
--- a/drivers/gpu/drm/udl/udl_dmabuf.c
+++ b/drivers/gpu/drm/udl/udl_dmabuf.c
@@ -90,8 +90,11 @@ static struct sg_table *udl_map_dma_buf(struct 
dma_buf_attachment *attach,
                return &udl_attach->sgt;

        if (!obj->pages) {
-               DRM_ERROR("pages is null.\n");
-               return ERR_PTR(-ENOMEM);
+               ret = udl_gem_get_pages(obj);
+               if (ret) {
+                       DRM_ERROR("failed to map pages.\n");
+                       return ERR_PTR(ret);
+               }
        }

        page_count = obj->base.size / PAGE_SIZE;
diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
index 1b132d7..80adbac 100644
--- a/drivers/gpu/drm/udl/udl_drv.h
+++ b/drivers/gpu/drm/udl/udl_drv.h
@@ -129,6 +129,8 @@ struct dma_buf *udl_gem_prime_export(struct drm_device *dev,
 struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
                                struct dma_buf *dma_buf);

+int udl_gem_get_pages(struct udl_gem_object *obj);
+void udl_gem_put_pages(struct udl_gem_object *obj);
 int udl_gem_vmap(struct udl_gem_object *obj);
 void udl_gem_vunmap(struct udl_gem_object *obj);
 int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index cd3482d..2a0a784 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -127,7 +127,7 @@ int udl_gem_fault(struct vm_area_struct *vma, struct 
vm_fault *vmf)
        }
 }

-static int udl_gem_get_pages(struct udl_gem_object *obj)
+int udl_gem_get_pages(struct udl_gem_object *obj)
 {
        struct page **pages;

@@ -143,7 +143,7 @@ static int udl_gem_get_pages(struct udl_gem_object *obj)
        return 0;
 }

-static void udl_gem_put_pages(struct udl_gem_object *obj)
+void udl_gem_put_pages(struct udl_gem_object *obj)
 {
        if (obj->base.import_attach) {
                drm_free_large(obj->pages);
-- 
2.2.0.rc0.207.ga3a616c