From 1f9910b41c857a892b83801feebdc7bdf38c5985 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Thu, 9 Jan 2025 10:55:53 +1000 Subject: nouveau/fence: handle cross device fences properly The fence sync logic doesn't handle a fence sync across devices as it tries to write to a channel offset from one device into the fence bo from a different device, which won't work so well. This patch fixes that to avoid using the sync path in the case where the fences come from different nouveau drm devices. This works fine on a single device as the fence bo is shared across the devices, and mapped into each channels vma space, the channel offsets are therefore okay to pass between sides, so one channel can sync on the seqnos from the other by using the offset into it's vma. Signed-off-by: Dave Airlie Cc: stable@vger.kernel.org Reviewed-by: Ben Skeggs [ Fix compilation issue; remove version log from commit messsage. - Danilo ] Signed-off-by: Danilo Krummrich Link: https://patchwork.freedesktop.org/patch/msgid/20250109005553.623947-1-airlied@gmail.com --- drivers/gpu/drm/nouveau/nouveau_fence.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c index 09686d038d60..7cc84472cece 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fence.c +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c @@ -387,11 +387,13 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, if (f) { struct nouveau_channel *prev; bool must_wait = true; + bool local; rcu_read_lock(); prev = rcu_dereference(f->channel); - if (prev && (prev == chan || - fctx->sync(f, prev, chan) == 0)) + local = prev && prev->cli->drm == chan->cli->drm; + if (local && (prev == chan || + fctx->sync(f, prev, chan) == 0)) must_wait = false; rcu_read_unlock(); if (!must_wait) -- cgit v1.2.3