Re: [PATCH 1/6] drm/bridge: aux-hpd: fix OF node leaks

From: Johan Hovold <johan@kernel.org>
To: Markus Elfring <Markus.Elfring@web.de>
Cc: Johan Hovold <johan+linaro@kernel.org>,
	freedreno@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-phy@lists.infradead.org, linux-arm-msm@vger.kernel.org,
	kernel-janitors@vger.kernel.org,
	Andrzej Hajda <andrzej.hajda@intel.com>,
	Bjorn Andersson <andersson@kernel.org>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@gmail.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Robert Foss <rfoss@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Vinod Koul <vkoul@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Abhinav Kumar <quic_abhinavk@quicinc.com>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Jonas Karlman <jonas@kwiboo.se>,
	Kishon Vijay Abraham I <kishon@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Kuogee Hsieh <quic_khsieh@quicinc.com>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Rob Clark <robdclark@gmail.com>
Subject: Re: [PATCH 1/6] drm/bridge: aux-hpd: fix OF node leaks
Date: Tue, 20 Feb 2024 08:24:55 +0100	[thread overview]
Message-ID: <ZdRTx2lmHBVlcLub@hovoldconsulting.com> (raw)
In-Reply-To: <c95f5ff3-8dad-4302-9384-92a9b83f7bdc@web.de>

On Mon, Feb 19, 2024 at 06:48:30PM +0100, Markus Elfring wrote:
> > The two device node references taken during allocation need to be
> > dropped when the auxiliary device is freed.
> …
> > +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> …
> > @@ -74,6 +75,8 @@ struct device *drm_dp_hpd_bridge_register(struct device *parent,
> >
> >  	ret = auxiliary_device_init(adev);
> >  	if (ret) {
> > +		of_node_put(adev->dev.platform_data);
> > +		of_node_put(adev->dev.of_node);
> >  		ida_free(&drm_aux_hpd_bridge_ida, adev->id);
> >  		kfree(adev);
> >  		return ERR_PTR(ret);
> 
> The last two statements are also used in a previous if branch.
> https://elixir.bootlin.com/linux/v6.8-rc5/source/drivers/gpu/drm/bridge/aux-hpd-bridge.c#L63
> 
> How do you think about to avoid such a bit of duplicate source code
> by adding a label here?

No, the current code is fine and what you are suggesting is in any case
unrelated to this fix.

If this function ever grows a third error path like that, I too would
consider it however.

Johan