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Message-ID: <33807d3c-9dd1-241a-ad23-0e0d4fba13e1@redhat.com>
Date:   Wed, 3 Nov 2021 14:09:05 +0100
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Subject: Re: [RESEND PATCH 2/5] drm: Move nomodeset kernel parameter handler
 to the DRM subsystem
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To:     Jani Nikula <jani.nikula@linux.intel.com>,
        linux-kernel@vger.kernel.org
Cc:     Peter Robinson <pbrobinson@gmail.com>,
        =?UTF-8?Q?Michel_D=c3=a4nzer?= <michel@daenzer.net>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Pekka Paalanen <pekka.paalanen@collabora.com>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Neal Gompa <ngompa13@gmail.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Ben Skeggs <bskeggs@redhat.com>, Chia-I Wu <olvaffe@gmail.com>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Dave Airlie <airlied@redhat.com>,
        David Airlie <airlied@linux.ie>,
        Gerd Hoffmann <kraxel@redhat.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Gurchetan Singh <gurchetansingh@chromium.org>,
        Hans de Goede <hdegoede@redhat.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        VMware Graphics <linux-graphics-maintainer@vmware.com>,
        Zack Rusin <zackr@vmware.com>, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
        linux-fbdev@vger.kernel.org, nouveau@lists.freedesktop.org,
        spice-devel@lists.freedesktop.org,
        virtualization@lists.linux-foundation.org
References: <20211103122809.1040754-1-javierm@redhat.com>
 <20211103122809.1040754-3-javierm@redhat.com> <87tugtbdob.fsf@intel.com>
From:   Javier Martinez Canillas <javierm@redhat.com>
In-Reply-To: <87tugtbdob.fsf@intel.com>
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Hello Jani,

On 11/3/21 13:56, Jani Nikula wrote:

[snip]

>>  
>> +obj-y += drm_nomodeset.o
> 
> This is a subtle functional change. With this, you'll always have
> __setup("nomodeset", text_mode) builtin and the parameter available. And
> using nomodeset will print out the pr_warn() splat from text_mode(). But
> removing nomodeset will have no impact if CONFIG_VGA_CONSOLE=n as that
> leads to vgacon_text_force() always returning false.
>

Yes, that's what I decided at the end to make it unconditional. That
way the same behaviour is preserved (even when only DRM drivers are
using the exported symbol).
 
> To not make functional changes, this should be:
> 
> obj-$(CONFIG_VGA_CONSOLE) += drm_nomodeset.o
>

Right, that should work.

> Now, going with the cleanup in this series, maybe we should make the
> functional change, and break the connection to CONFIG_VGA_CONSOLE
> altogether, also in the header?
> 
> (Maybe we'll also need a proxy drm kconfig option to only have
> drm_modeset.o builtin when CONFIG_DRM != n.)
>

See my other email. I believe the issue is drivers/gpu/drm always
being included even when CONFIG_DRM is not set.

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