diff options
| author | Erik Kurzinger <ekurzinger@nvidia.com> | 2024-02-21 10:44:28 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-01 13:41:59 +0100 |
| commit | 66eeda9463ef3dc192431488a1e2631a57e904ef (patch) | |
| tree | c46d3543950051c012c3099e3c41a7a676721a78 | |
| parent | f06e56215c9e0349a67d172e96aab6ce0ec1d586 (diff) | |
drm/syncobj: handle NULL fence in syncobj_eventfd_entry_func
[ Upstream commit 2aa6f5b0fd052e363bb9d4b547189f0bf6b3d6d3 ]
During syncobj_eventfd_entry_func, dma_fence_chain_find_seqno may set
the fence to NULL if the given seqno is signaled and a later seqno has
already been submitted. In that case, the eventfd should be signaled
immediately which currently does not happen.
This is a similar issue to the one addressed by commit b19926d4f3a6
("drm/syncobj: Deal with signalled fences in drm_syncobj_find_fence.").
As a fix, if the return value of dma_fence_chain_find_seqno indicates
success but it sets the fence to NULL, we will assign a stub fence to
ensure the following code still signals the eventfd.
v1 -> v2: assign a stub fence instead of signaling the eventfd
Signed-off-by: Erik Kurzinger <ekurzinger@nvidia.com>
Fixes: c7a472297169 ("drm/syncobj: add IOCTL to register an eventfd")
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20240221184527.37667-1-ekurzinger@nvidia.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/drm_syncobj.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index b3433265be6a..5860428da8de 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -1380,10 +1380,21 @@ syncobj_eventfd_entry_func(struct drm_syncobj *syncobj, /* This happens inside the syncobj lock */ fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1)); + if (!fence) + return; + ret = dma_fence_chain_find_seqno(&fence, entry->point); - if (ret != 0 || !fence) { + if (ret != 0) { + /* The given seqno has not been submitted yet. */ dma_fence_put(fence); return; + } else if (!fence) { + /* If dma_fence_chain_find_seqno returns 0 but sets the fence + * to NULL, it implies that the given seqno is signaled and a + * later seqno has already been submitted. Assign a stub fence + * so that the eventfd still gets signaled below. + */ + fence = dma_fence_get_stub(); } list_del_init(&entry->node); |