From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/atomic: Check that the config funcs exist drm_mode_alloc Date: Wed, 8 May 2019 10:35:19 +0200 Message-ID: <20190508083519.GS17751@phenom.ffwll.local> References: <1557256451-24950-1-git-send-email-jcrouse@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1557256451-24950-1-git-send-email-jcrouse@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Jordan Crouse Cc: freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, Sean Paul , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, David Airlie , Maarten Lankhorst , Maxime Ripard , Daniel Vetter List-Id: dri-devel@lists.freedesktop.org On Tue, May 07, 2019 at 01:14:11PM -0600, Jordan Crouse wrote: > An error while initializing the msm driver ends up calling > drm_atomic_helper_shutdown() without first initializing the funcs > in mode_config. While I'm not 100% sure this isn't a ordering > problem in msm adding a check to drm_mode_alloc seems like > a nice and safe solution. > > Signed-off-by: Jordan Crouse Hm yeah this looks a bit too much like ducttape. I think Noralf started working on some ideas of devm-like automatic cleanup for drm stuff (we cannot use devm, that has the wrong lifetimes, despite all the drivers using it). Simple fix would be to move up the assignment of config.funcs to be much earlier in your driver load I guess. -Daniel > --- > > drivers/gpu/drm/drm_atomic.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c > index 5eb4013..1729428 100644 > --- a/drivers/gpu/drm/drm_atomic.c > +++ b/drivers/gpu/drm/drm_atomic.c > @@ -114,6 +114,9 @@ drm_atomic_state_alloc(struct drm_device *dev) > { > struct drm_mode_config *config = &dev->mode_config; > > + if (!config->funcs) > + return NULL; > + > if (!config->funcs->atomic_state_alloc) { > struct drm_atomic_state *state; > > -- > 2.7.4 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch