Re: [PATCH RFC v1 00/52] drm/crtc: Rename struct drm_crtc::dev to drm_dev

From: Jani Nikula <jani.nikula@intel.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: "Geert Uytterhoeven" <geert+renesas@glider.be>,
	"Xinliang Liu" <xinliang.liu@linaro.org>,
	"Tomi Valkeinen" <tomi.valkeinen+renesas@ideasonboard.com>,
	"Alexey Kodanev" <aleksei.kodanev@bell-sw.com>,
	dri-devel@lists.freedesktop.org,
	"Vandita Kulkarni" <vandita.kulkarni@intel.com>,
	"Alim Akhtar" <alim.akhtar@samsung.com>,
	"Anitha Chrisanthus" <anitha.chrisanthus@intel.com>,
	"Marijn Suijten" <marijn.suijten@somainline.org>,
	"Jonathan Hunter" <jonathanh@nvidia.com>,
	"Arun R Murthy" <arun.r.murthy@intel.com>,
	"Jerome Brunet" <jbrunet@baylibre.com>,
	"Liu Shixin" <liushixin2@huawei.com>,
	linux-samsung-soc@vger.kernel.org,
	"Samuel Holland" <samuel@sholland.org>,
	"Matt Roper" <matthew.d.roper@intel.com>,
	"Wenjing Liu" <wenjing.liu@amd.com>,
	"Javier Martinez Canillas" <javierm@redhat.com>,
	"Stanislav Lisovskiy" <stanislav.lisovskiy@intel.com>,
	"Danilo Krummrich" <dakr@redhat.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	spice-devel@lists.freedesktop.org,
	"Niranjana Vishwanathapura" <niranjana.vishwanathapura@intel.com>,
	linux-sunxi@lists.linux.dev, "Stylon Wang" <stylon.wang@amd.com>,
	"Tim Huang" <Tim.Huang@amd.com>,
	"Suraj Kandpal" <suraj.kandpal@intel.com>,
	"André Almeida" <andrealmeid@igalia.com>,
	"Andi Shyti" <andi.shyti@linux.intel.com>,
	"Yifan Zhang" <yifan1.zhang@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Lucas De Marchi" <lucas.demarchi@intel.com>,
	"Hersen Wu" <hersenxs.wu@amd.com>,
	"Jessica Zhang" <quic_jesszhan@quicinc.com>,
	"Kamlesh Gurudasani" <kamlesh.gurudasani@gmail.com>,
	"Bhawanpreet Lakha" <Bhawanpreet.Lakha@amd.com>,
	"Łukasz Bartosik" <lb@semihalf.com>,
	"Radhakrishna Sripada" <radhakrishna.sripada@intel.com>,
	"Andrew Jeffery" <andrew@aj.id.au>,
	"Seung-Woo Kim" <sw0312.kim@samsung.com>,
	"Noralf Trønnes" <noralf@tronnes.org>,
	kernel@pengutronix.de, "Alex Deucher" <alexander.deucher@amd.com>,
	freedreno@lists.freedesktop.org,
	"Claudiu Beznea" <claudiu.beznea@microchip.com>,
	"Gerd Hoffmann" <kraxel@redhat.com>,
	"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	linux-aspeed@lists.ozlabs.org, nouveau@lists.freedesktop.org,
	"Mitul Golani" <mitulkumar.ajitkumar.golani@intel.com>,
	"José Roberto de Souza" <jose.souza@intel.com>,
	virtualization@lists.linux-foundation.org,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Yongqin Liu" <yongqin.liu@linaro.org>,
	"Mario Limonciello" <mario.limonciello@amd.com>,
	"Fei Yang" <fei.yang@intel.com>,
	"David Lechner" <david@lechnology.com>,
	"Juha-Pekka Heikkila" <juhapekka.heikkila@gmail.com>,
	"Jiri Slaby (SUSE)" <jirislaby@kernel.org>,
	"David Francis" <David.Francis@amd.com>,
	"Aaron Liu" <aaron.liu@amd.com>,
	"Vinod Polimera" <quic_vpolimer@quicinc.com>,
	linux-rockchip@lists.infradead.org,
	"Fangzhi Zuo" <jerry.zuo@amd.com>,
	"Aurabindo Pillai" <aurabindo.pillai@amd.com>,
	"VMware Graphics Reviewers"
	<linux-graphics-maintainer@vmware.com>,
	"Ben Skeggs" <bskeggs@redhat.com>,
	"Jouni Högander" <jouni.hogander@intel.com>,
	"Dave Airlie" <airlied@redhat.com>,
	linux-mips@vger.kernel.org,
	"Maxime Coquelin" <mcoquelin.stm32@gmail.com>,
	"Gurchetan Singh" <gurchetansingh@chromium.org>,
	"Martin Blumenstingl" <martin.blumenstingl@googlemail.com>,
	linux-arm-msm@vger.kernel.org,
	"Animesh Manna" <animesh.manna@intel.com>,
	linux-renesas-soc@vger.kernel.org,
	"Maxime Ripard" <mripard@kernel.org>,
	"Chaitanya Kumar Borah" <chaitanya.kumar.borah@intel.com>,
	"Biju Das" <biju.das.jz@bp.renesas.com>,
	linux-amlogic@lists.infradead.org,
	"Evan Quan" <evan.quan@amd.com>,
	"Michal Simek" <michal.simek@amd.com>,
	linux-arm-kernel@lists.infradead.org,
	"Sean Paul" <sean@poorly.run>,
	"Neil Armstrong" <neil.armstrong@linaro.org>,
	"Kai Vehmanen" <kai.vehmanen@linux.intel.com>,
	"Boris Brezillon" <bbrezillon@kernel.org>,
	"Chunyan Zhang" <zhang.lyra@gmail.com>,
	"Qingqing Zhuo" <qingqing.zhuo@amd.com>,
	"Sandy Huang" <hjc@rock-chips.com>,
	"Swati Sharma" <swati2.sharma@intel.com>,
	"John Stultz" <jstultz@google.com>,
	"Paul Kocialkowski" <paul.kocialkowski@bootlin.com>,
	"Kyungmin Park" <kyungmin.park@samsung.com>,
	"Drew Davenport" <ddavenport@chromium.org>,
	"Kevin Hilman" <khilman@baylibre.com>,
	"Hawking Zhang" <Hawking.Zhang@amd.com>,
	"Haneen Mohammed" <hamohammed.sa@gmail.com>,
	"Anusha Srivatsa" <anusha.srivatsa@intel.com>,
	"Dan Carpenter" <error27@gmail.com>,
	"Karol Herbst" <kherbst@redhat.com>,
	linux-hyperv@vger.kernel.org,
	"Melissa Wen" <melissa.srw@gmail.com>,
	"Maíra Canal" <mairacanal@riseup.net>,
	"Luca Coelho" <luciano.coelho@intel.com>,
	"Laurent Pinchart" <laurent.pinchart@ideasonboard.com>,
	"Andrzej Hajda" <andrzej.hajda@intel.com>,
	"Likun Gao" <Likun.Gao@amd.com>,
	"Sam Ravnborg" <sam@ravnborg.org>,
	"Alain Volmat" <alain.volmat@foss.st.com>,
	"Xinwei Kong" <kong.kongxinwei@hisilicon.com>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Deepak Rawat" <drawat.floss@gmail.com>,
	"Chen-Yu Tsai" <wens@csie.org>, "Joel Stanley" <joel@jms.id.au>,
	"Ankit Nautiyal" <ankit.k.nautiyal@intel.com>,
	"Sumit Semwal" <sumit.semwal@linaro.org>,
	"Alan Liu" <haoping.liu@amd.com>,
	"Philip Yang" <Philip.Yang@amd.com>,
	intel-gfx@lists.freedesktop.org,
	"Alison Wang" <alison.wang@nxp.com>,
	"Wolfram Sang" <wsa+renesas@sang-engineering.com>,
	"Abhinav Kumar" <quic_abhinavk@quicinc.com>,
	"Gustavo Sousa" <gustavo.sousa@intel.com>,
	"Baolin Wang" <baolin.wang@linux.alibaba.com>,
	"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
	"Mikko Perttunen" <mperttunen@nvidia.com>,
	"Tvrtko Ursulin" <tvrtko.ursulin@linux.intel.com>,
	"Rodrigo Siqueira" <rodrigosiqueiramelo@gmail.com>,
	"Tomi Valkeinen" <tomba@kernel.org>,
	"Deepak R Varma" <drv@mailo.com>,
	"Pan, Xinhui" <Xinhui.Pan@amd.com>,
	"Konrad Dybcio" <konrad.dybcio@linaro.org>,
	"Kieran Bingham" <kieran.bingham+renesas@ideasonboard.com>,
	"Tian Tao" <tiantao6@hisilicon.com>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Christian König" <christian.koenig@amd.com>,
	"Khaled Almahallawy" <khaled.almahallawy@intel.com>,
	linux-stm32@st-md-mailman.stormreply.com,
	"Emma Anholt" <emma@anholt.net>,
	"Chun-Kuang Hu" <chunkuang.hu@kernel.org>,
	"Liviu Dudau" <liviu.dudau@arm.com>,
	"Alexandre Torgue" <alexandre.torgue@foss.st.com>,
	"Roman Li" <roman.li@amd.com>,
	"Paul Cercueil" <paul@crapouillou.net>,
	"Hamza Mahfooz" <hamza.mahfooz@amd.com>,
	"Marek Vasut" <marex@denx.de>,
	"Jiapeng Chong" <jiapeng.chong@linux.alibaba.com>,
	xen-devel@lists.xenproject.org,
	"Guchun Chen" <guchun.chen@amd.com>,
	"Oleksandr Andrushchenko" <oleksandr_andrushchenko@epam.com>,
	"Raphael Gallais-Pou" <raphael.gallais-pou@foss.st.com>,
	"Rodrigo Siqueira" <Rodrigo.Siqueira@amd.com>,
	"Russell King" <linux@armlinux.org.uk>,
	"Uma Shankar" <uma.shankar@intel.com>,
	"Mika Kahola" <mika.kahola@intel.com>,
	"Jiasheng Jiang" <jiasheng@iscas.ac.cn>,
	"Srinivasan Shanmugam" <srinivasan.shanmugam@amd.com>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"Vinod Govindapillai" <vinod.govindapillai@intel.com>,
	linux-tegra@vger.kernel.org, "Marek Olšák" <marek.olsak@amd.com>,
	"Joaquín Ignacio Aramendía" <samsagax@gmail.com>,
	"Melissa Wen" <mwen@igalia.com>,
	"Hans de Goede" <hdegoede@redhat.com>,
	linux-mediatek@lists.infradead.org,
	"Laurentiu Palcu" <laurentiu.palcu@oss.nxp.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"David Tadokoro" <davidbtadokoro@usp.br>,
	"AngeloGioacchino Del Regno"
	<angelogioacchino.delregno@collabora.com>,
	"Orson Zhai" <orsonzhai@gmail.com>,
	amd-gfx@lists.freedesktop.org, "Jyri Sarha" <jyri.sarha@iki.fi>,
	"Yannick Fertre" <yannick.fertre@foss.st.com>,
	"Nicolas Ferre" <nicolas.ferre@microchip.com>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski@linaro.org>,
	"Philippe Cornu" <philippe.cornu@foss.st.com>,
	"Wayne Lin" <Wayne.Lin@amd.com>,
	"Dmitry Baryshkov" <dmitry.baryshkov@linaro.org>,
	"Nirmoy Das" <nirmoy.das@intel.com>, "Lang Yu" <Lang.Yu@amd.com>
Subject: Re: [PATCH RFC v1 00/52] drm/crtc: Rename struct drm_crtc::dev to drm_dev
Date: Thu, 13 Jul 2023 12:03:05 +0300	[thread overview]
Message-ID: <878rbkgp4m.fsf@intel.com> (raw)
In-Reply-To: <20230712161025.22op3gtzgujrhytb@pengutronix.de>

On Wed, 12 Jul 2023, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
> Hello Jani,
>
> On Wed, Jul 12, 2023 at 05:34:28PM +0300, Jani Nikula wrote:
>> On Wed, 12 Jul 2023, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
>> > Hello,
>> >
>> > while I debugged an issue in the imx-lcdc driver I was constantly
>> > irritated about struct drm_device pointer variables being named "dev"
>> > because with that name I usually expect a struct device pointer.
>> >
>> > I think there is a big benefit when these are all renamed to "drm_dev".
>> > I have no strong preference here though, so "drmdev" or "drm" are fine
>> > for me, too. Let the bikesheding begin!
>> >
>> > Some statistics:
>> >
>> > $ git grep -ohE 'struct drm_device *\* *[^ (),;]*' v6.5-rc1 | sort | uniq -c | sort -n
>> >       1 struct drm_device *adev_to_drm
>> >       1 struct drm_device *drm_
>> >       1 struct drm_device          *drm_dev
>> >       1 struct drm_device        *drm_dev
>> >       1 struct drm_device *pdev
>> >       1 struct drm_device *rdev
>> >       1 struct drm_device *vdev
>> >       2 struct drm_device *dcss_drv_dev_to_drm
>> >       2 struct drm_device **ddev
>> >       2 struct drm_device *drm_dev_alloc
>> >       2 struct drm_device *mock
>> >       2 struct drm_device *p_ddev
>> >       5 struct drm_device *device
>> >       9 struct drm_device * dev
>> >      25 struct drm_device *d
>> >      95 struct drm_device *
>> >     216 struct drm_device *ddev
>> >     234 struct drm_device *drm_dev
>> >     611 struct drm_device *drm
>> >    4190 struct drm_device *dev
>> >
>> > This series starts with renaming struct drm_crtc::dev to drm_dev. If
>> > it's not only me and others like the result of this effort it should be
>> > followed up by adapting the other structs and the individual usages in
>> > the different drivers.
>> 
>> I think this is an unnecessary change. In drm, a dev is usually a drm
>> device, i.e. struct drm_device *.
>
> Well, unless it's not. Prominently there is
>
> 	struct drm_device {
> 		...
> 		struct device *dev;
> 		...
> 	};
>
> which yields quite a few code locations using dev->dev which is
> IMHO unnecessary irritating:
>
> 	$ git grep '\<dev->dev' v6.5-rc1 drivers/gpu/drm | wc -l
> 	1633
>
> Also the functions that deal with both a struct device and a struct
> drm_device often use "dev" for the struct device and then "ddev" for
> the drm_device (see for example amdgpu_device_get_pcie_replay_count()).

Why is specifically struct drm_device *dev so irritating to you?

You lead us to believe it's an outlier in kernel, something that goes
against common kernel style, but it's really not:

$ git grep -how "struct [A-Za-z0-9_]\+ \*dev" | sort | uniq -c | sort -rn | head -20
  38494 struct device *dev
  16388 struct net_device *dev
   4184 struct drm_device *dev
   2780 struct pci_dev *dev
   1916 struct comedi_device *dev
   1510 struct mlx5_core_dev *dev
   1057 struct mlx4_dev *dev
    894 struct b43_wldev *dev
    762 struct input_dev *dev
    623 struct usbnet *dev
    561 struct mlx5_ib_dev *dev
    525 struct mt76_dev *dev
    465 struct mt76x02_dev *dev
    435 struct platform_device *dev
    431 struct usb_device *dev
    411 struct mt7915_dev *dev
    398 struct cx231xx *dev
    378 struct mei_device *dev
    363 struct ksz_device *dev
    359 struct mthca_dev *dev

A good portion of the above also have a dev member.

Are you planning on changing all of the above too, or are you only
annoyed by drm?

I'm really not convinced at all.

BR,
Jani.

-- 
Jani Nikula, Intel Open Source Graphics Center