From 3a5a5971bc1fe34a9a24b59118db0b3a1f9c2902 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 11 May 2020 11:35:50 +0200 Subject: [PATCH] drm/udl: Don't call get/put_pages on imported dma-buf There's no direct harm, because for the shmem helpers these are noops on imported buffers. The trouble is in the locks these take - I want to change dma_buf_vmap locking, and so need to make sure that we only ever take certain locks on one side of the dma-buf interface: Either for exporters, or for importers. Acked-by: Thomas Zimmermann Signed-off-by: Daniel Vetter Cc: Dave Airlie Cc: Sean Paul Cc: Gerd Hoffmann Cc: Thomas Zimmermann Cc: Alex Deucher Cc: Daniel Vetter Cc: Thomas Gleixner Cc: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200511093554.211493-6-daniel.vetter@ffwll.ch --- drivers/gpu/drm/udl/udl_gem.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c index b6e26f9..c68d3e2 100644 --- a/drivers/gpu/drm/udl/udl_gem.c +++ b/drivers/gpu/drm/udl/udl_gem.c @@ -46,29 +46,31 @@ static void *udl_gem_object_vmap(struct drm_gem_object *obj) if (shmem->vmap_use_count++ > 0) goto out; - ret = drm_gem_shmem_get_pages(shmem); - if (ret) - goto err_zero_use; - - if (obj->import_attach) + if (obj->import_attach) { shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); - else + } else { + ret = drm_gem_shmem_get_pages(shmem); + if (ret) + goto err; + shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL); + if (!shmem->vaddr) + drm_gem_shmem_put_pages(shmem); + } + if (!shmem->vaddr) { DRM_DEBUG_KMS("Failed to vmap pages\n"); ret = -ENOMEM; - goto err_put_pages; + goto err; } out: mutex_unlock(&shmem->vmap_lock); return shmem->vaddr; -err_put_pages: - drm_gem_shmem_put_pages(shmem); -err_zero_use: +err: shmem->vmap_use_count = 0; mutex_unlock(&shmem->vmap_lock); return ERR_PTR(ret); -- 2.7.4