This is a note to let you know that I've just added the patch titled
nouveau: offload fence uevents work to workqueue
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nouveau-offload-fence-uevents-work-to-workqueue.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 39126abc5e20611579602f03b66627d7cd1422f0 Mon Sep 17 00:00:00 2001
From: Dave Airlie <airlied@xxxxxxxxxx>
Date: Mon, 29 Jan 2024 11:26:45 +1000
Subject: nouveau: offload fence uevents work to workqueue
From: Dave Airlie <airlied@xxxxxxxxxx>
commit 39126abc5e20611579602f03b66627d7cd1422f0 upstream.
This should break the deadlock between the fctx lock and the irq lock.
This offloads the processing off the work from the irq into a workqueue.
Cc: linux-stable@xxxxxxxxxxxxxxx
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/576237/
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nouveau_fence.c | 24 ++++++++++++++++++------
drivers/gpu/drm/nouveau/nouveau_fence.h | 1 +
2 files changed, 19 insertions(+), 6 deletions(-)
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -103,6 +103,7 @@ nouveau_fence_context_kill(struct nouvea
void
nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
{
+ cancel_work_sync(&fctx->uevent_work);
nouveau_fence_context_kill(fctx, 0);
nvif_event_dtor(&fctx->event);
fctx->dead = 1;
@@ -145,12 +146,13 @@ nouveau_fence_update(struct nouveau_chan
return drop;
}
-static int
-nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc)
+static void
+nouveau_fence_uevent_work(struct work_struct *work)
{
- struct nouveau_fence_chan *fctx = container_of(event, typeof(*fctx), event);
+ struct nouveau_fence_chan *fctx = container_of(work, struct nouveau_fence_chan,
+ uevent_work);
unsigned long flags;
- int ret = NVIF_EVENT_KEEP;
+ int drop = 0;
spin_lock_irqsave(&fctx->lock, flags);
if (!list_empty(&fctx->pending)) {
@@ -160,11 +162,20 @@ nouveau_fence_wait_uevent_handler(struct
fence = list_entry(fctx->pending.next, typeof(*fence), head);
chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));
if (nouveau_fence_update(chan, fctx))
- ret = NVIF_EVENT_DROP;
+ drop = 1;
}
+ if (drop)
+ nvif_event_block(&fctx->event);
+
spin_unlock_irqrestore(&fctx->lock, flags);
+}
- return ret;
+static int
+nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc)
+{
+ struct nouveau_fence_chan *fctx = container_of(event, typeof(*fctx), event);
+ schedule_work(&fctx->uevent_work);
+ return NVIF_EVENT_KEEP;
}
void
@@ -178,6 +189,7 @@ nouveau_fence_context_new(struct nouveau
} args;
int ret;
+ INIT_WORK(&fctx->uevent_work, nouveau_fence_uevent_work);
INIT_LIST_HEAD(&fctx->flip);
INIT_LIST_HEAD(&fctx->pending);
spin_lock_init(&fctx->lock);
--- a/drivers/gpu/drm/nouveau/nouveau_fence.h
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.h
@@ -44,6 +44,7 @@ struct nouveau_fence_chan {
u32 context;
char name[32];
+ struct work_struct uevent_work;
struct nvif_event event;
int notify_ref, dead, killed;
};
Patches currently in stable-queue which might be from airlied@xxxxxxxxxx are
queue-6.6/nouveau-offload-fence-uevents-work-to-workqueue.patch
