Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751522AbdGZLhW (ORCPT ); Wed, 26 Jul 2017 07:37:22 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36593 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751031AbdGZLhU (ORCPT ); Wed, 26 Jul 2017 07:37:20 -0400 Date: Wed, 26 Jul 2017 13:37:17 +0200 From: Daniel Vetter To: Eric Anholt Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/3] drm/vc4: Convert more lock requirement comments to lockdep assertions. Message-ID: <20170726113717.quih436edhizixgu@phenom.ffwll.local> Mail-Followup-To: Eric Anholt , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20170725182718.31468-1-eric@anholt.net> <20170725182718.31468-3-eric@anholt.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170725182718.31468-3-eric@anholt.net> X-Operating-System: Linux phenom 4.11.0-2-amd64 User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2411 Lines: 75 On Tue, Jul 25, 2017 at 11:27:18AM -0700, Eric Anholt wrote: > Since I do my development with lockdep on, this will help make sure I > don't introduce bugs here. Yeah it's somewhat annoying that lockdep_assert_held doesn't reduce to a "no false positives, maybe some false negatives, but real fast" runtime check without lockdep and just mutex debugging enabled. We even have it as mutex_is_locked already. But not doing to fight that bikeshed :-/ > Signed-off-by: Eric Anholt Reviewed-by: Daniel Vetter > --- > drivers/gpu/drm/vc4/vc4_bo.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c > index f4387e1e178d..b24dd8685590 100644 > --- a/drivers/gpu/drm/vc4/vc4_bo.c > +++ b/drivers/gpu/drm/vc4/vc4_bo.c > @@ -163,10 +163,12 @@ static uint32_t bo_page_index(size_t size) > return (size / PAGE_SIZE) - 1; > } > > -/* Must be called with bo_lock held. */ > static void vc4_bo_destroy(struct vc4_bo *bo) > { > struct drm_gem_object *obj = &bo->base.base; > + struct vc4_dev *vc4 = to_vc4_dev(obj->dev); > + > + lockdep_assert_held(&vc4->bo_lock); > > vc4_bo_set_label(obj, -1); > > @@ -181,9 +183,11 @@ static void vc4_bo_destroy(struct vc4_bo *bo) > drm_gem_cma_free_object(obj); > } > > -/* Must be called with bo_lock held. */ > static void vc4_bo_remove_from_cache(struct vc4_bo *bo) > { > + struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev); > + > + lockdep_assert_held(&vc4->bo_lock); > list_del(&bo->unref_head); > list_del(&bo->size_head); > } > @@ -367,12 +371,13 @@ int vc4_dumb_create(struct drm_file *file_priv, > return ret; > } > > -/* Must be called with bo_lock held. */ > static void vc4_bo_cache_free_old(struct drm_device *dev) > { > struct vc4_dev *vc4 = to_vc4_dev(dev); > unsigned long expire_time = jiffies - msecs_to_jiffies(1000); > > + lockdep_assert_held(&vc4->bo_lock); > + > while (!list_empty(&vc4->bo_cache.time_list)) { > struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list, > struct vc4_bo, unref_head); > -- > 2.11.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch