drm/nouveau: protect channel create/destroy and irq handler with a spinlock
The nv50 pgraph handler (for example) could reenable pgraph fifo access
and that would be bad when pgraph context is being unloaded (we need the
guarantee a ctxprog isn't running).
Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
index 2281f99..f7ca950 100644
--- a/drivers/gpu/drm/nouveau/nouveau_channel.c
+++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
@@ -275,9 +275,18 @@
*/
nouveau_fence_fini(chan);
- /* Ensure the channel is no longer active on the GPU */
+ /* This will prevent pfifo from switching channels. */
pfifo->reassign(dev, false);
+ /* We want to give pgraph a chance to idle and get rid of all potential
+ * errors. We need to do this before the lock, otherwise the irq handler
+ * is unable to process them.
+ */
+ if (pgraph->channel(dev) == chan)
+ nouveau_wait_for_idle(dev);
+
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+
pgraph->fifo_access(dev, false);
if (pgraph->channel(dev) == chan)
pgraph->unload_context(dev);
@@ -293,6 +302,8 @@
pfifo->reassign(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
/* Release the channel's resources */
nouveau_gpuobj_ref_del(dev, &chan->pushbuf);
if (chan->pushbuf_bo) {