From d5c1e84b3a130f0743b218b33ff7d9cb493ab5b4 Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Date: Tue, 14 Jan 2014 16:48:58 +0100
Subject: [PATCH] drm/nouveau: hold mutex while syncing to kernel channel
Not holding the mutex potentially causes corruption of the kernel
channel when page flipping.
Cc: stable@vger.kernel.org #3.13
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---
drivers/gpu/drm/nouveau/nouveau_display.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index 25ea82f8def3..8b757483a107 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -603,6 +603,14 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
if (!s)
return -ENOMEM;
+ if (new_bo != old_bo) {
+ ret = nouveau_bo_pin(new_bo, TTM_PL_FLAG_VRAM);
+ if (ret)
+ goto fail_free;
+ }
+
+ mutex_lock(&chan->cli->mutex);
+
/* synchronise rendering channel with the kernel's channel */
spin_lock(&new_bo->bo.bdev->fence_lock);
fence = nouveau_fence_ref(new_bo->bo.sync_obj);
@@ -612,13 +620,6 @@ nouveau_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
if (ret)
goto fail_free;
- if (new_bo != old_bo) {
- ret = nouveau_bo_pin(new_bo, TTM_PL_FLAG_VRAM);
- if (ret)
- goto fail_free;
- }
-
- mutex_lock(&chan->cli->mutex);
ret = ttm_bo_reserve(&old_bo->bo, true, false, false, NULL);
if (ret)
goto fail_unpin;
--
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