Commit 3a5a5971 authored May 11, 2020 by Daniel Vetter

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 <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200511093554.211493-6-daniel.vetter@ffwll.ch

parent d323bb44

drivers/gpu/drm/udl/udl_gem.c

+12 −10

Original line number	Diff line number	Diff line
		@@ -46,29 +46,31 @@ static void udl_gem_object_vmap(struct drm_gem_object obj)
		if (shmem->vmap_use_count++ > 0)
		goto out;

		if (obj->import_attach) {
		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
		} else {
		ret = drm_gem_shmem_get_pages(shmem);
		if (ret)
		goto err_zero_use;
		goto err;

		if (obj->import_attach)
		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
		else
		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);

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