From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752300AbeCEHB6 (ORCPT ); Mon, 5 Mar 2018 02:01:58 -0500 Received: from regular1.263xmail.com ([211.150.99.136]:37056 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751215AbeCEHB4 (ORCPT ); Mon, 5 Mar 2018 02:01:56 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: jeffy.chen@rock-chips.com X-FST-TO: laurent.pinchart@ideasonboard.com X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: jeffy.chen@rock-chips.com X-UNIQUE-TAG: <6b57628ecb5fdce9a9495a477f8849f2> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Message-ID: <5A9CEB44.40207@rock-chips.com> Date: Mon, 05 Mar 2018 15:01:24 +0800 From: JeffyChen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:19.0) Gecko/20130126 Thunderbird/19.0 MIME-Version: 1.0 To: Laurent Pinchart , Enric Balletbo i Serra CC: Sandy Huang , =?UTF-8?B?SGVpa28gU3TDvGJuZXI=?= , Andrzej Hajda , linux-rockchip@lists.infradead.org, Archit Taneja , linux-kernel@vger.kernel.org, Russell King , Neil Armstrong , dri-devel@lists.freedesktop.org, Jose Abreu , Hans Verkuil , Jernej Skrabec , linux-arm-kernel@lists.infradead.org, David Airlie , kernel@collabora.com, Daniel Vetter , Sean Paul Subject: Re: [PATCH v9 5/5] drm/bridge/synopsys: dw-hdmi: Add missing bridge detach References: <20180302175757.28192-1-enric.balletbo@collabora.com> <20180302175757.28192-6-enric.balletbo@collabora.com> <2714218.VptbnhJPkd@avalon> <5A99EA37.6070006@rock-chips.com> In-Reply-To: <5A99EA37.6070006@rock-chips.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Laurent, sorry, you're right, this patch should not be needed. the connector should be cleanup by drm_mode_config_cleanup->drm_connector_put. i did that in analogix_dp is to avoid a use-after-free issue not kmemleak, because the connector was allocated/freed in analogix_dp's bind/unbind. but i found a kmemleak issue(dma_mask not freed) in dw-hdmi when testing that, will send patch soon. On 03/03/2018 08:20 AM, JeffyChen wrote: > Hi Laurent, > > On 03/03/2018 05:49 AM, Laurent Pinchart wrote: >> Hi Enric, >> >> Thank you for the patch. >> >> On Friday, 2 March 2018 19:57:57 EET Enric Balletbo i Serra wrote: >>> From: Jeffy Chen >>> >>> We inited connector in attach(), so need a detach() to cleanup. >> >> Do we ? The dw-hdmi driver already sets drm_connector_cleanup() as the >> connector .destroy() handler, and the .destroy() operation is called >> by the >> DRM core. None of the other bridge drivers call drm_connector_cleanup() >> directly. > > hmmm, checking the code, there are also lots of drivers do the > cleanup(drm_connector_cleanup or funcs->destroy): > drm# grep -r "connector.*funcs->destroy" . > ./rockchip/inno_hdmi.c: hdmi->connector.funcs->destroy(&hdmi->connector); > ./rockchip/cdn-dp-core.c: connector->funcs->destroy(connector); > ./bridge/analogix/analogix_dp_core.c: > dp->connector.funcs->destroy(&dp->connector); > ./msm/hdmi/hdmi.c: hdmi->connector->funcs->destroy(hdmi->connector); > ./msm/dsi/dsi.c: msm_dsi->connector->funcs->destroy(msm_dsi->connector); > ./msm/edp/edp.c: edp->connector->funcs->destroy(edp->connector); > ./zte/zx_hdmi.c: hdmi->connector.funcs->destroy(&hdmi->connector); > ./drm_connector.c: connector->funcs->destroy(connector); > ./drm_connector.c: connector->funcs->destroy(connector); > ./nouveau/dispnv04/disp.c: connector->funcs->destroy(connector); > ./nouveau/nv50_display.c: mstc->connector.funcs->destroy(&mstc->connector); > ./nouveau/nv50_display.c: connector->funcs->destroy(connector); > > > > when i debug analogix_dp bind/unbind, i found that we need to cleanup > the connector(reported by kmemleak). so i added it to > ./bridge/analogix/analogix_dp_core.c...after that i saw dw-hdmi missing > that too(by checking the code), so make this patch. > > but i didn't really tested it on devices using dw-hdmi, so i'm not very > sure the dw-hdmi(maybe also other bridges) is the same with analogix_dp. > > i can try to find a chromebook veyron to check it next week :) > > but even there's a leak, i'm still not very sure about: > should the caller of drm_connector_init cleanup it > or the caller of drm_bridge_attach should do it(for example > analogix_dp_bind/analogix_dp_unbind) > or should the DRM core take care of that? > >> >>> Signed-off-by: Jeffy Chen >>> Signed-off-by: Thierry Escande >>> Signed-off-by: Enric Balletbo i Serra >>> ---