From 3945e47543863385b54d94c94b023ee7ca9df972 Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Mon, 18 Oct 2010 03:53:39 +0200 Subject: drm/nouveau: Refactor context destruction to avoid a lock ordering issue. The destroy_context() engine hooks call gpuobj management functions to release the channel resources, these functions use HARDIRQ-unsafe locks whereas destroy_context() is called with the HARDIRQ-safe context_switch_lock held, that's a lock ordering violation. Push the engine-specific channel destruction logic into destroy_context() and let the hardware-specific code lock and unlock when it's actually needed. Change the engine destruction order to avoid a race in the small gap between pgraph and pfifo context uninitialization. Reported-by: Marcin Slusarz Signed-off-by: Francisco Jerez Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nv50_fifo.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/gpu/drm/nouveau/nv50_fifo.c') diff --git a/drivers/gpu/drm/nouveau/nv50_fifo.c b/drivers/gpu/drm/nouveau/nv50_fifo.c index 815960fe4f43..d3295aae0c4e 100644 --- a/drivers/gpu/drm/nouveau/nv50_fifo.c +++ b/drivers/gpu/drm/nouveau/nv50_fifo.c @@ -292,10 +292,23 @@ void nv50_fifo_destroy_context(struct nouveau_channel *chan) { struct drm_device *dev = chan->dev; + struct drm_nouveau_private *dev_priv = dev->dev_private; + struct nouveau_fifo_engine *pfifo = &dev_priv->engine.fifo; struct nouveau_gpuobj *ramfc = NULL; + unsigned long flags; NV_DEBUG(dev, "ch%d\n", chan->id); + spin_lock_irqsave(&dev_priv->context_switch_lock, flags); + pfifo->reassign(dev, false); + + /* Unload the context if it's the currently active one */ + if (pfifo->channel_id(dev) == chan->id) { + pfifo->disable(dev); + pfifo->unload_context(dev); + pfifo->enable(dev); + } + /* This will ensure the channel is seen as disabled. */ nouveau_gpuobj_ref(chan->ramfc, &ramfc); nouveau_gpuobj_ref(NULL, &chan->ramfc); @@ -306,6 +319,10 @@ nv50_fifo_destroy_context(struct nouveau_channel *chan) nv50_fifo_channel_disable(dev, 127); nv50_fifo_playlist_update(dev); + pfifo->reassign(dev, true); + spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags); + + /* Free the channel resources */ nouveau_gpuobj_ref(NULL, &ramfc); nouveau_gpuobj_ref(NULL, &chan->cache); } -- cgit