From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A47CDC433DB for ; Wed, 24 Mar 2021 02:18:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77665619B3 for ; Wed, 24 Mar 2021 02:18:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234826AbhCXCR7 (ORCPT ); Tue, 23 Mar 2021 22:17:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234753AbhCXCR2 (ORCPT ); Tue, 23 Mar 2021 22:17:28 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2056EC061763; Tue, 23 Mar 2021 19:17:28 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 5A638580; Wed, 24 Mar 2021 03:17:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1616552245; bh=qmQLAPlk4G6/WYtsOH5D1LVgkD6Jy8yQNYSAiaOxFOM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hjiGesnakNcI11YiR1n37fS+ZicFYib3eqRR5Y7wvWep3+rnjl0gVNb9/y/w0mWFK cn3qV2pdgV9GiX9wF7zX9O3cV9Ut8MMpyy+iHoUY2x6iU9bHMmtUbnMuyfXjmbOBIh C8mLVldMPkFMu9fJNqiEmRkziuUZO/F5ClsnnvgA= Date: Wed, 24 Mar 2021 04:16:43 +0200 From: Laurent Pinchart To: Paul Cercueil Cc: David Airlie , Daniel Vetter , Jernej Skrabec , Neil Armstrong , Jonas Karlman , linux-mips@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Andrzej Hajda , od@zcrc.me, stable@vger.kernel.org, Sam Ravnborg Subject: Re: [PATCH v3 1/4] drm: bridge/panel: Cleanup connector on bridge detach Message-ID: References: <20210124085552.29146-1-paul@crapouillou.net> <20210124085552.29146-2-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210124085552.29146-2-paul@crapouillou.net> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Hi Paul, Thank you for the patch. On Sun, Jan 24, 2021 at 08:55:49AM +0000, Paul Cercueil wrote: > If we don't call drm_connector_cleanup() manually in > panel_bridge_detach(), the connector will be cleaned up with the other > DRM objects in the call to drm_mode_config_cleanup(). However, since our > drm_connector is devm-allocated, by the time drm_mode_config_cleanup() > will be called, our connector will be long gone. Therefore, the > connector must be cleaned up when the bridge is detached to avoid > use-after-free conditions. > > v2: Cleanup connector only if it was created > > v3: Add FIXME > > Fixes: 13dfc0540a57 ("drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge.") > Cc: # 4.12+ > Cc: Andrzej Hajda > Cc: Neil Armstrong > Cc: Laurent Pinchart > Cc: Jonas Karlman > Cc: Jernej Skrabec > Signed-off-by: Paul Cercueil > --- > drivers/gpu/drm/bridge/panel.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c > index 0ddc37551194..5959e8183cd0 100644 > --- a/drivers/gpu/drm/bridge/panel.c > +++ b/drivers/gpu/drm/bridge/panel.c > @@ -87,6 +87,18 @@ static int panel_bridge_attach(struct drm_bridge *bridge, > > static void panel_bridge_detach(struct drm_bridge *bridge) > { > + struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge); > + struct drm_connector *connector = &panel_bridge->connector; > + > + /* > + * Cleanup the connector if we know it was initialized. > + * > + * FIXME: This wouldn't be needed if the panel_bridge structure was > + * allocated with drmm_kzalloc(). This might be tricky since the > + * drm_device pointer can only be retrieved when the bridge is attached. > + */ > + if (!!panel_bridge->connector.dev) How about simply if (connector->dev) ? With this change, Reviewed-by: Laurent Pinchart > + drm_connector_cleanup(connector); > } > > static void panel_bridge_pre_enable(struct drm_bridge *bridge) -- Regards, Laurent Pinchart