iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

nouveau: push event block/allowing out of the fence context

Browse Source 
There is a deadlock between the irq and fctx locks,
the irq handling takes irq then fctx lock
the fence signalling takes fctx then irq lock

This splits the fence signalling path so the code that hits
the irq lock is done in a separate work queue.

This seems to fix crashes/hangs when using nouveau gsp with
i915 primary GPU.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231222043308.3090089-11-airlied@gmail.com
This commit is contained in:
Dave Airlie 2023-12-22 14:31:59 +10:00 committed by Dave Airlie
parent 9c9dd22ba5
commit eacabb5462
2 changed files with 27 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/gpu/drm/nouveau/nouveau_fence.c
View File

@ -62,7 +62,7 @@ nouveau_fence_signal(struct nouveau_fence *fence)
if (test_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags)) {
struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
if (!--fctx->notify_ref)
if (atomic_dec_and_test(&fctx->notify_ref))
drop = 1;
}
@ -103,6 +103,7 @@ nouveau_fence_context_kill(struct nouveau_fence_chan *fctx, int error)
void
nouveau_fence_context_del(struct nouveau_fence_chan *fctx)
{
cancel_work_sync(&fctx->allow_block_work);
nouveau_fence_context_kill(fctx, 0);
nvif_event_dtor(&fctx->event);
fctx->dead = 1;
@ -167,6 +168,18 @@ nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc
return ret;
}
static void
nouveau_fence_work_allow_block(struct work_struct *work)
{
struct nouveau_fence_chan *fctx = container_of(work, struct nouveau_fence_chan,
allow_block_work);
if (atomic_read(&fctx->notify_ref) == 0)
nvif_event_block(&fctx->event);
else
nvif_event_allow(&fctx->event);
}
void
nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_chan *fctx)
{
@ -178,6 +191,7 @@ nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_cha
} args;
int ret;
INIT_WORK(&fctx->allow_block_work, nouveau_fence_work_allow_block);
INIT_LIST_HEAD(&fctx->flip);
INIT_LIST_HEAD(&fctx->pending);
spin_lock_init(&fctx->lock);
@ -521,15 +535,19 @@ static bool nouveau_fence_enable_signaling(struct dma_fence *f)
struct nouveau_fence *fence = from_fence(f);
struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
bool ret;
bool do_work;
if (!fctx->notify_ref++)
nvif_event_allow(&fctx->event);
if (atomic_inc_return(&fctx->notify_ref) == 0)
do_work = true;
ret = nouveau_fence_no_signaling(f);
if (ret)
set_bit(DMA_FENCE_FLAG_USER_BITS, &fence->base.flags);
else if (!--fctx->notify_ref)
nvif_event_block(&fctx->event);
else if (atomic_dec_and_test(&fctx->notify_ref))
do_work = true;
if (do_work)
schedule_work(&fctx->allow_block_work);
return ret;
}

5
drivers/gpu/drm/nouveau/nouveau_fence.h
View File

@ -3,6 +3,7 @@
#define __NOUVEAU_FENCE_H__
#include <linux/dma-fence.h>
#include <linux/workqueue.h>
#include <nvif/event.h>
struct nouveau_drm;
@ -45,7 +46,9 @@ struct nouveau_fence_chan {
char name[32];
struct nvif_event event;
int notify_ref, dead, killed;
struct work_struct allow_block_work;
atomic_t notify_ref;
int dead, killed;
};
struct nouveau_fence_priv {