From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1BAEE3D45D5; Tue, 29 Sep 2026 14:42:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.25 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790692973; cv=none; b=rUrcxh0/z024pwevBazG3H+5w3317hEOD4z0XF/+53GEJDgA+kbLcljVzTvXH/ezWrU/y3qSXz5BwwOHGrg3kRYazw18XobaWEPfoGWjxGxPuy0qjsXMKGZy83MMCnao+eednSc6tAnKylRPZTBIWVRzU8SabsliMRa3Hec96V0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790692973; c=relaxed/simple; bh=BWNukz3gxR4ofTYhCcg6SCY61hjz0FbNIyj2Ss/lLgs=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=pIG15uUIUjeElW6t9CBGI8oCAcxVx9Er2m9JTfamGF9Y0ZcsxNqBTiNSPNtsKJ83HWdqUZoVv7VT5NYw4ojnhU189QFeliHraUpGkGg4UiAJaxSZNKx2HKIcdyKNj1Twvnd6XisLKVZ0rVSB+plMeJaoJAjTW1S9LvDM1qqiaHs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from edelgard.fodlan.icenowy.me (unknown [112.94.101.54]) by APP-05 (Coremail) with SMTP id zQCowAC3IDtEzrtqWCqvCQ--.41306S2; Tue, 29 Sep 2026 22:42:15 +0800 (CST) Message-ID: Subject: Re: [PATCH v2 2/7] drm: verisilicon: stop using deprecated devm_drm_of_get_bridge() From: Icenowy Zheng To: Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Frank Li , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Dave Stevenson , =?ISO-8859-1?Q?Ma=EDra?= Canal , Raspberry Pi Kernel Maintenance , Geert Uytterhoeven Cc: Arnd Bergmann , Doug Anderson , Hui Pu , Ian Ray , Thomas Petazzoni , dri-devel@lists.freedesktop.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, kernel test robot Date: Tue, 29 Sep 2026 22:42:12 +0800 In-Reply-To: <20260929-drm-fix-of_get_bridge-build-regression-v2-2-6da431d8f180@bootlin.com> References: <20260929-drm-fix-of_get_bridge-build-regression-v2-0-6da431d8f180@bootlin.com> <20260929-drm-fix-of_get_bridge-build-regression-v2-2-6da431d8f180@bootlin.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID:zQCowAC3IDtEzrtqWCqvCQ--.41306S2 X-Coremail-Antispam: 1UD129KBjvJXoWxAry7Jr15Kw43Cw1DZFWkZwb_yoWrJF1rpF 40qa98try5XrWxXw42kr4j9FyYya4Dtw4rGFWUt34Fvr1FqF4DGF1kAry5Z3W5CF17GF1r tr4DtFySv3W8Aa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvvb7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4 A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IE w4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMc vjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY 1x0262kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8Jw C20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAF wI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjx v20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2 jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73Uj IFyTuYvjxUv4EEDUUUU X-CM-SenderInfo: x2kh0wp0lqwv3d6l2u1dvotugofq/ =E5=9C=A8 2026-09-29=E4=BA=8C=E7=9A=84 15:39 +0200=EF=BC=8CLuca Ceresoli=E5= =86=99=E9=81=93=EF=BC=9A > devm_drm_of_get_bridge() is deprecated, switch to > of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() > returns > a refcounted bridge, ensure it is put by using bridge.next_bridge. >=20 > Fixes build failure when CONFIG_OF is disabled. >=20 > Fixes: aa8a8c7e4641 ("drm/bridge: panel: move all code to > drm_panel.c") > Reported-by: Arnd Bergmann > Closes: > https://lore.kernel.org/r/20260928161605.2271412-1-arnd@kernel.org > Reported-by: kernel test robot > Closes: > https://lore.kernel.org/oe-kbuild-all/202609291109.OIsGTysr-lkp@intel.com= / > Closes: > https://lore.kernel.org/oe-kbuild-all/202609290408.BOs7sk55-lkp@intel.com= / > Signed-off-by: Luca Ceresoli Checked the code in drm_bridge.c, and it looks like the lifetime of next_bridge should be indirectly managed by devm when devm_drm_bridge_alloc() successes and the next_bridge field assigned, so the only explicit put needed here should be in the alloc failure path. Patch is: ``` Reviewed-by: Icenowy Zheng ``` >=20 > --- >=20 > Changes in v2: > - fix bridge reference leak on attach error path It should be `bridge alloc error` instead of `attach error`, but I don't know how to correct the error in the changelog, and anyway it won't be part of the final commit. Thanks, Icenowy > - mention lkp report > --- > =C2=A0drivers/gpu/drm/verisilicon/vs_bridge.c | 11 ++++++----- > =C2=A0drivers/gpu/drm/verisilicon/vs_bridge.h |=C2=A0 1 - > =C2=A02 files changed, 6 insertions(+), 6 deletions(-) >=20 > diff --git a/drivers/gpu/drm/verisilicon/vs_bridge.c > b/drivers/gpu/drm/verisilicon/vs_bridge.c > index dc7c85b07fe3..3a5091c0ac2c 100644 > --- a/drivers/gpu/drm/verisilicon/vs_bridge.c > +++ b/drivers/gpu/drm/verisilicon/vs_bridge.c > @@ -29,7 +29,7 @@ static int vs_bridge_attach(struct drm_bridge > *bridge, > =C2=A0{ > =C2=A0 struct vs_bridge *vbridge =3D drm_bridge_to_vs_bridge(bridge); > =C2=A0 > - return drm_bridge_attach(encoder, vbridge->next_bridge, > + return drm_bridge_attach(encoder, vbridge->base.next_bridge, > =C2=A0 bridge, flags); > =C2=A0} > =C2=A0 > @@ -303,8 +303,7 @@ struct vs_bridge *vs_bridge_init(struct > drm_device *drm_dev, > =C2=A0 return NULL; > =C2=A0 } > =C2=A0 > - next =3D devm_drm_of_get_bridge(drm_dev->dev, drm_dev->dev- > >of_node, > - =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 output, intf); > + next =3D of_drm_get_bridge_by_endpoint(drm_dev->dev->of_node, > output, intf); > =C2=A0 if (IS_ERR(next)) { > =C2=A0 ret =3D PTR_ERR(next); > =C2=A0 if (ret !=3D -EPROBE_DEFER) > @@ -321,12 +320,14 @@ struct vs_bridge *vs_bridge_init(struct > drm_device *drm_dev, > =C2=A0 > =C2=A0 bridge =3D devm_drm_bridge_alloc(drm_dev->dev, struct > vs_bridge, base, > =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 bridge_funcs); > - if (IS_ERR(bridge)) > + if (IS_ERR(bridge)) { > + drm_bridge_put(next); > =C2=A0 return ERR_PTR(PTR_ERR(bridge)); > + } > =C2=A0 > =C2=A0 bridge->crtc =3D crtc; > =C2=A0 bridge->intf =3D intf; > - bridge->next_bridge =3D next; > + bridge->base.next_bridge =3D next; > =C2=A0 > =C2=A0 if (intf =3D=3D VSDC_OUTPUT_INTERFACE_DPI) > =C2=A0 enctype =3D DRM_MODE_ENCODER_DPI; > diff --git a/drivers/gpu/drm/verisilicon/vs_bridge.h > b/drivers/gpu/drm/verisilicon/vs_bridge.h > index 70fee1749699..2b0ed94e4520 100644 > --- a/drivers/gpu/drm/verisilicon/vs_bridge.h > +++ b/drivers/gpu/drm/verisilicon/vs_bridge.h > @@ -25,7 +25,6 @@ struct vs_bridge { > =C2=A0 struct drm_connector *conn; > =C2=A0 > =C2=A0 struct vs_crtc *crtc; > - struct drm_bridge *next_bridge; > =C2=A0 enum vs_bridge_output_interface intf; > =C2=A0}; > =C2=A0