From 55647c139cf7d6caeaa08a99b2165763a02ab71a Mon Sep 17 00:00:00 2001
From: Ben Skeggs <bskeggs@redhat.com>
Date: Thu, 30 Sep 2010 09:09:42 +1000
Subject: [PATCH] drm/nv50: prevent (IB_PUT == IB_GET) for occurring unless idle
Should fix a DMA race condition I've never seen myself, but could be
the culprit in some random hangs that have been reported.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---
drivers/gpu/drm/nouveau/nouveau_dma.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_dma.c b/drivers/gpu/drm/nouveau/nouveau_dma.c
index 9d27acd..eb24e2b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dma.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dma.c
@@ -214,7 +214,7 @@ nv50_dma_push_wait(struct nouveau_channel *chan, int count)
chan->dma.ib_free = get - chan->dma.ib_put;
if (chan->dma.ib_free <= 0)
- chan->dma.ib_free += chan->dma.ib_max + 1;
+ chan->dma.ib_free += chan->dma.ib_max;
}
return 0;
--
1.7.2.2