Message-ID: <91c6b455-62cd-cec7-8445-e93c99230a03@redhat.com>
Date:   Thu, 16 Dec 2021 01:13:56 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.3.0
Subject: Re: [PATCH 00/60] drm: Make all drivers to honour the nomodeset
 parameter
Content-Language: en-US
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        =?UTF-8?Q?Heiko_St=c3=bcbner?= <heiko@sntech.de>,
        "James (Qian) Wang" <james.qian.wang@arm.com>,
        =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= <noralf@tronnes.org>,
        Alexey Brodkin <abrodkin@synopsys.com>,
        Alison Wang <alison.wang@nxp.com>,
        Anitha Chrisanthus <anitha.chrisanthus@intel.com>,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>,
        Boris Brezillon <bbrezillon@kernel.org>,
        Brian Starkey <brian.starkey@arm.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        David Lechner <david@lechnology.com>,
        Deepak Rawat <drawat.floss@gmail.com>,
        Edmund Dea <edmund.j.dea@intel.com>,
        Emma Anholt <emma@anholt.net>,
        Erico Nunes <nunes.erico@gmail.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Hyun Kwon <hyun.kwon@xilinx.com>,
        Inki Dae <inki.dae@samsung.com>, Joel Stanley <joel@jms.id.au>,
        Joonyoung Shim <jy0922.shim@samsung.com>,
        Jyri Sarha <jyri.sarha@iki.fi>,
        Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>,
        Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Liviu Dudau <liviu.dudau@arm.com>,
        Lucas Stach <l.stach@pengutronix.de>,
        Marek Vasut <marex@denx.de>,
        Maxime Ripard <mripard@kernel.org>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>,
        Patrik Jakobsson <patrik.r.jakobsson@gmail.com>,
        Paul Cercueil <paul@crapouillou.net>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Philippe Cornu <philippe.cornu@foss.st.com>,
        Qiang Yu <yuq825@gmail.com>, Rob Clark <robdclark@gmail.com>,
        Rob Herring <robh@kernel.org>,
        Russell King <linux+etnaviv@armlinux.org.uk>,
        Russell King <linux@armlinux.org.uk>,
        Sam Ravnborg <sam@ravnborg.org>,
        Sandy Huang <hjc@rock-chips.com>, Sean Paul <sean@poorly.run>,
        Stefan Agner <stefan@agner.ch>,
        Thierry Reding <thierry.reding@gmail.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Tian Tao <tiantao6@hisilicon.com>,
        Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        Tomi Valkeinen <tomba@kernel.org>,
        Xinliang Liu <xinliang.liu@linaro.org>,
        Yannick Fertre <yannick.fertre@foss.st.com>
References: <20211215010008.2545520-1-javierm@redhat.com>
 <Ybp7qDs1p3x5GzNJ@pendragon.ideasonboard.com>
From:   Javier Martinez Canillas <javierm@redhat.com>
In-Reply-To: <Ybp7qDs1p3x5GzNJ@pendragon.ideasonboard.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hello Laurent,

On 12/16/21 00:35, Laurent Pinchart wrote:

[snip]

>>
>> I've built tested with 'make allmodconfig && make M=drivers/gpu/drm/', but
>> only booted in a few devices with and without nomodeset in the cmdline. So
>> testing and reviewing for all the drivers would be highly appreciated.
> 
> The fact that the series is so big makes me think it would be better to
> handle this in the DRM core. Is there any way we could do so ? Otherwise
> we'll chase this issue forever in new drivers, and will be plagued with
> cargo cult problems.
> 

Yes, what Thomas suggested is to add a set of drm_module_{pci,platform}_driver()
macros in include/drm/drm_drv.h, that will just check whether the driver should
be registered or not and call the {pci,platform}_register_driver() functions.

That way the change in the drivers would just be something like the following:

-module_platform_driver(malidp_platform_driver);
+drm_module_platform_driver(malidp_platform_driver);

There are some drivers that still need a custom module init functions for various
reasons (e.g: register a set of devices/drivers, need to be a late init call, etc)
but at least for most drivers this should be handled transparently as long as they
use these drm_*_register_driver() macros.

So just ignore this series and I'll post a v2 soon.

Best regards,
-- 
Javier Martinez Canillas
Linux Engineering
Red Hat