Fix a sparse warning with this message "warning:dereference of noderef expression". In this context it means we are dereferencing a __rcu tagged pointer directly. We should not be directly dereferencing a rcu pointer. To get a normal (non __rcu tagged pointer) from a __rcu tagged pointer we are using the function unrcu_pointer(...). The non __rcu tagged pointer then can be dereferenced just like a normal pointer. I tested with qemu with this command qemu-system-x86_64 \ -m 2G \ -smp 2 \ -kernel bzImage \ -append "console=ttyS0 root=/dev/sda earlyprintk=serial net.ifnames=0" \ -drive file=bullseye.img,format=raw \ -net user,host=10.0.2.10,hostfwd=tcp:127.0.0.1:10021-:22 \ -net nic,model=e1000 \ -enable-kvm \ -nographic \ -pidfile vm.pid \ 2>&1 | tee vm.log with lockdep enabled. Signed-off-by: Abhinav Singh <singhabhinav9051571833@xxxxxxxxx> --- drivers/gpu/drm/nouveau/nv10_fence.c | 2 +- drivers/gpu/drm/nouveau/nv84_fence.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nv10_fence.c b/drivers/gpu/drm/nouveau/nv10_fence.c index c6a0db5b9e21..845b64c079ed 100644 --- a/drivers/gpu/drm/nouveau/nv10_fence.c +++ b/drivers/gpu/drm/nouveau/nv10_fence.c @@ -32,7 +32,7 @@ int nv10_fence_emit(struct nouveau_fence *fence) { - struct nvif_push *push = fence->channel->chan.push; + struct nvif_push *push = unrcu_pointer(fence->channel)->chan.push; int ret = PUSH_WAIT(push, 2); if (ret == 0) { PUSH_MTHD(push, NV06E, SET_REFERENCE, fence->base.seqno); diff --git a/drivers/gpu/drm/nouveau/nv84_fence.c b/drivers/gpu/drm/nouveau/nv84_fence.c index 812b8c62eeba..d42e72e23dec 100644 --- a/drivers/gpu/drm/nouveau/nv84_fence.c +++ b/drivers/gpu/drm/nouveau/nv84_fence.c @@ -85,7 +85,7 @@ nv84_fence_chid(struct nouveau_channel *chan) static int nv84_fence_emit(struct nouveau_fence *fence) { - struct nouveau_channel *chan = fence->channel; + struct nouveau_channel *chan = unrcu_pointer(fence->channel); struct nv84_fence_chan *fctx = chan->fence; u64 addr = fctx->vma->addr + nv84_fence_chid(chan) * 16; -- 2.39.2