drm/ttm/nouveau: don't call tt destroy callback on alloc failure.

This is confusing, and from my reading of all the drivers only
nouveau got this right.

Just make the API act under driver control of it's own allocation
failing, and don't call destroy, if the page table fails to
create there is nothing to cleanup here.

(I'm willing to believe I've missed something here, so please
review deeply).

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200728041736.20689-1-airlied@gmail.com

diff --git a/drivers/gpu/drm/nouveau/nouveau_sgdma.c b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
index 20b6d0b..c3ccf66 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_sgdma.c
+++ b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
@@ -95,12 +95,9 @@ nouveau_sgdma_create_ttm(struct ttm_buffer_object *bo, uint32_t page_flags)
        else
                nvbe->ttm.ttm.func = &nv50_sgdma_backend;
 
-       if (ttm_dma_tt_init(&nvbe->ttm, bo, page_flags))
-               /*
-                * A failing ttm_dma_tt_init() will call ttm_tt_destroy()
-                * and thus our nouveau_sgdma_destroy() hook, so we don't need
-                * to free nvbe here.
-                */
+       if (ttm_dma_tt_init(&nvbe->ttm, bo, page_flags)) {
+               kfree(nvbe);
                return NULL;
+       }
        return &nvbe->ttm.ttm;
 }

diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index bab6787..9d1c717 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -244,7 +244,6 @@ int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
        ttm_tt_init_fields(ttm, bo, page_flags);
 
        if (ttm_tt_alloc_page_directory(ttm)) {
-               ttm_tt_destroy(ttm);
                pr_err("Failed allocating page table\n");
                return -ENOMEM;
        }
@@ -268,7 +267,6 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_buffer_object *bo,
 
        INIT_LIST_HEAD(&ttm_dma->pages_list);
        if (ttm_dma_tt_alloc_page_directory(ttm_dma)) {
-               ttm_tt_destroy(ttm);
                pr_err("Failed allocating page table\n");
                return -ENOMEM;
        }
@@ -290,7 +288,6 @@ int ttm_sg_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_buffer_object *bo,
        else
                ret = ttm_dma_tt_alloc_page_directory(ttm_dma);
        if (ret) {
-               ttm_tt_destroy(ttm);
                pr_err("Failed allocating page table\n");
                return -ENOMEM;
        }