Nouveau - Jan 2010 - [PATCH] drm/nouveau: call ttm_bo_wait with the bo lock held to prevent hang

nouveau_gem_ioctl_cpu_prep calls ttm_bo_wait without the bo lock held.
ttm_bo_wait unlocks that lock, and so must be called with it held.

Currently this bug causes libdrm nouveau_bo_busy() to hang the machine.

Signed-off-by: Luca Barbieri <luca at luca-barbieri.com>
---
 drivers/gpu/drm/nouveau/nouveau_gem.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c
b/drivers/gpu/drm/nouveau/nouveau_gem.c
index eab55f8..c00a91f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -925,7 +925,9 @@ nouveau_gem_ioctl_cpu_prep(struct drm_device *dev, void
*data,
 	}
 
 	if (req->flags & NOUVEAU_GEM_CPU_PREP_NOBLOCK) {
+		spin_lock(&nvbo->bo.lock);
 		ret = ttm_bo_wait(&nvbo->bo, false, false, no_wait);
+		spin_unlock(&nvbo->bo.lock);
 	} else {
 		ret = ttm_bo_synccpu_write_grab(&nvbo->bo, no_wait);
 		if (ret == 0)
-- 
1.6.3.3

Please apply or state objections to this patch.

Thanks.

Looks sane to me, it would be nice if someone else also agreed, before
committing.

On Thu, Jan 28, 2010 at 5:28 PM, Luca Barbieri <luca at luca-barbieri.com>
wrote:
> Please apply or state objections to this patch.
>
> Thanks.
> _______________________________________________
> Nouveau mailing list
> Nouveau at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/nouveau
>

Acked-by: Maarten Maathuis <madman2003 at gmail.com>

On Thu, Jan 28, 2010 at 10:33 PM, Maarten Maathuis <madman2003 at
gmail.com> wrote:
> Looks sane to me, it would be nice if someone else also agreed, before
> committing.
>
> On Thu, Jan 28, 2010 at 5:28 PM, Luca Barbieri <luca at
luca-barbieri.com> wrote:
>> Please apply or state objections to this patch.
>>
>> Thanks.
>> _______________________________________________
>> Nouveau mailing list
>> Nouveau at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/nouveau
>>
>