Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 14dba717 authored by Thomas Hellstrom's avatar Thomas Hellstrom
Browse files

drm/vmwgfx: Reorganize the fence wait loop 



Reorganize the fence wait loop somewhat to make it look more like the
examples in set_current_state() kerneldoc, and add some code comments.

Also if we're about to time out, make sure we check again whether the fence
is actually signaled.

Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: default avatarBrian Paul <brianp@vmware.com>
Reviewed-by: default avatarDeepak Rawat <drawat@vmware.com>
parent 3fbeccf8

drivers/gpu/drm/vmwgfx/vmwgfx_fence.c

+26 −12
Original line number Diff line number Diff line
@@ -175,7 +175,6 @@ static long vmw_fence_wait(struct dma_fence *f, bool intr, signed long timeout) 
	struct vmw_private *dev_priv = fman->dev_priv;

	struct vmwgfx_wait_cb cb;

	long ret = timeout;

	unsigned long irq_flags;



	if (likely(vmw_fence_obj_signaled(fence)))

		return timeout;
@@ -183,7 +182,7 @@ static long vmw_fence_wait(struct dma_fence *f, bool intr, signed long timeout) 
	vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);

	vmw_seqno_waiter_add(dev_priv);



	spin_lock_irqsave(f->lock, irq_flags);

	spin_lock(f->lock);



	if (intr && signal_pending(current)) {

		ret = -ERESTARTSYS;
@@ -194,30 +193,45 @@ static long vmw_fence_wait(struct dma_fence *f, bool intr, signed long timeout) 
	cb.task = current;

	list_add(&cb.base.node, &f->cb_list);



	while (ret > 0) {

	for (;;) {

		__vmw_fences_update(fman);

		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags))

			break;



		/*

		 * We can use the barrier free __set_current_state() since

		 * DMA_FENCE_FLAG_SIGNALED_BIT + wakeup is protected by the

		 * fence spinlock.

		 */

		if (intr)

			__set_current_state(TASK_INTERRUPTIBLE);

		else

			__set_current_state(TASK_UNINTERRUPTIBLE);

		spin_unlock_irqrestore(f->lock, irq_flags);



		ret = schedule_timeout(ret);

		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags)) {

			if (ret == 0 && timeout > 0)

				ret = 1;

			break;

		}



		spin_lock_irqsave(f->lock, irq_flags);

		if (ret > 0 && intr && signal_pending(current))

		if (intr && signal_pending(current)) {

			ret = -ERESTARTSYS;

			break;

		}



		if (ret == 0)

			break;



		spin_unlock(f->lock);



		ret = schedule_timeout(ret);



		spin_lock(f->lock);

	}

	__set_current_state(TASK_RUNNING);

	if (!list_empty(&cb.base.node))

		list_del(&cb.base.node);

	__set_current_state(TASK_RUNNING);



out:

	spin_unlock_irqrestore(f->lock, irq_flags);

	spin_unlock(f->lock);



	vmw_seqno_waiter_remove(dev_priv);