From 0fbecd400dd0a82d465b3086f209681e8c54cb0f Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Tue, 21 Sep 2010 02:15:15 +0200 Subject: [PATCH] drm/ttm: Clear the ghost cpu_writers flag on ttm_buffer_object_transfer. It makes sense for a BO to move after a process has requested exclusive RW access on it (e.g. because the BO used to be located in unmappable VRAM and we intercepted the CPU access from the fault handler). If we let the ghost object inherit cpu_writers from the original object, ttm_bo_release_list() will raise a kernel BUG when the ghost object is destroyed. This can be reproduced with the nouveau driver on nv5x. Reported-by: Marcin Slusarz Reviewed-by: Jerome Glisse Tested-by: Marcin Slusarz Signed-off-by: Francisco Jerez Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/ttm_bo_util.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index 7cffb3e04232..3451a82adba7 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -351,6 +351,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo, INIT_LIST_HEAD(&fbo->lru); INIT_LIST_HEAD(&fbo->swap); fbo->vm_node = NULL; + atomic_set(&fbo->cpu_writers, 0); fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj); kref_init(&fbo->list_kref);