From: Christian König <christian.koenig@xxxxxxx> commit 721255b52700b320c4ae2e23d57f7d9ad1db50b9 upstream. It is illegal to add a dma_fence_chain as timeline point. Flatten out the fences into a dma_fence_array instead. Signed-off-by: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Nirmoy Das <nirmoy.das@xxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20220209182600.434803-1-christian.koenig@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_syncobj.c | 61 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 56 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -853,12 +853,57 @@ drm_syncobj_fd_to_handle_ioctl(struct dr &args->handle); } + +/* + * Try to flatten a dma_fence_chain into a dma_fence_array so that it can be + * added as timeline fence to a chain again. + */ +static int drm_syncobj_flatten_chain(struct dma_fence **f) +{ + struct dma_fence_chain *chain = to_dma_fence_chain(*f); + struct dma_fence *tmp, **fences; + struct dma_fence_array *array; + unsigned int count; + + if (!chain) + return 0; + + count = 0; + dma_fence_chain_for_each(tmp, &chain->base) + ++count; + + fences = kmalloc_array(count, sizeof(*fences), GFP_KERNEL); + if (!fences) + return -ENOMEM; + + count = 0; + dma_fence_chain_for_each(tmp, &chain->base) + fences[count++] = dma_fence_get(tmp); + + array = dma_fence_array_create(count, fences, + dma_fence_context_alloc(1), + 1, false); + if (!array) + goto free_fences; + + dma_fence_put(*f); + *f = &array->base; + return 0; + +free_fences: + while (count--) + dma_fence_put(fences[count]); + + kfree(fences); + return -ENOMEM; +} + static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private, struct drm_syncobj_transfer *args) { struct drm_syncobj *timeline_syncobj = NULL; - struct dma_fence *fence; struct dma_fence_chain *chain; + struct dma_fence *fence; int ret; timeline_syncobj = drm_syncobj_find(file_private, args->dst_handle); @@ -869,16 +914,22 @@ static int drm_syncobj_transfer_to_timel args->src_point, args->flags, &fence); if (ret) - goto err; + goto err_put_timeline; + + ret = drm_syncobj_flatten_chain(&fence); + if (ret) + goto err_free_fence; + chain = dma_fence_chain_alloc(); if (!chain) { ret = -ENOMEM; - goto err1; + goto err_free_fence; } + drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point); -err1: +err_free_fence: dma_fence_put(fence); -err: +err_put_timeline: drm_syncobj_put(timeline_syncobj); return ret;
