From 72fec10c17d95bcb99371f5b29f6947e67d7493b Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 11 Dec 2020 17:29:42 +0100 Subject: [PATCH] drm/ttm: WARN_ON non-empty lru when disabling a resource manager MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ttm_resource_manager->use_type is only used for runtime changes by vmwgfx. I think ideally we'd push this functionality into drivers - ttm itself does not provide any locking to guarantee this is safe, so the only way this can work at runtime is if the driver does provide additional guarantees. vwmgfx does that through the vmw_private->reservation_sem. Therefore supporting this feature in shared code feels a bit misplaced. As a first step add a WARN_ON to make sure the resource manager is empty. This is just to make sure I actually understand correctly what vmwgfx is doing, and to make sure an eventual subsequent refactor doesn't break anything. This check should also be useful for other drivers, to make sure they haven't leaked anything. Reviewed-by: Roland Scheidegger Reviewed-by: Christian König Signed-off-by: Daniel Vetter Cc: Christian Koenig Cc: Huang Rui Link: https://patchwork.freedesktop.org/patch/msgid/20201211162942.3399050-3-daniel.vetter@ffwll.ch --- include/drm/ttm/ttm_resource.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h index ad6da99770e9..da0ed7e8c915 100644 --- a/include/drm/ttm/ttm_resource.h +++ b/include/drm/ttm/ttm_resource.h @@ -190,6 +190,10 @@ struct ttm_resource { static inline void ttm_resource_manager_set_used(struct ttm_resource_manager *man, bool used) { + int i; + + for (i = 0; i < TTM_MAX_BO_PRIORITY; i++) + WARN_ON(!list_empty(&man->lru[i])); man->use_type = used; }