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Message-ID: <82731e7d-e34f-46c4-8f54-c5d7d3d60b5a@suse.de>
Date: Thu, 16 May 2024 17:11:10 +0200
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Subject: Re: [PATCH] ACPI: video: Fix name collision with architecture's
 video.o
To: Hans de Goede <hdegoede@redhat.com>, "Rafael J. Wysocki"
 <rafael@kernel.org>
Cc: lenb@kernel.org, arnd@arndb.de, chaitanya.kumar.borah@intel.com,
 suresh.kumar.kurmi@intel.com, jani.saarinen@intel.com,
 linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
 intel-gfx@lists.freedesktop.org, linux-arch@vger.kernel.org,
 linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org
References: <20240516124317.710-1-tzimmermann@suse.de>
 <CAJZ5v0gw620SLfxM66FfVeWMTN=dSZZtpH-=mFT_0HsumT3SsA@mail.gmail.com>
 <1850b44d-e468-44db-82b7-f57e77fe49ba@redhat.com>
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From: Thomas Zimmermann <tzimmermann@suse.de>
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In-Reply-To: <1850b44d-e468-44db-82b7-f57e77fe49ba@redhat.com>
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Hi

Am 16.05.24 um 17:03 schrieb Hans de Goede:
> Hi,
>
> On 5/16/24 3:04 PM, Rafael J. Wysocki wrote:
>> CC Hans who has been doing the majority of the ACPI video work.
>>
>> On Thu, May 16, 2024 at 2:43 PM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>>> Commit 2fd001cd3600 ("arch: Rename fbdev header and source files")
>>> renames the video source files under arch/ such that they does not
>>> refer to fbdev any longer. The new files named video.o conflict with
>>> ACPI's video.ko module.
>> And surely nobody knew or was unable to check upfront that there was a
>> video.ko already in the kernel.
> Sorry, but nack for this change. I very deliberately kept the module-name
> as video when renaming the actual .c file from video.c to acpi_video.c
> because many people pass drivers/video/acpi_video.c module arguments
> on the kernel commandline using video.param=val .
>
> Try e.g. doing a duckduckgo search for 1 off:
>
> "video.only_lcd"
> "video.allow_duplicates"
> "video.brightness_switch_enabled"

Ok, that makes sense. I'll rename the other files.

Best regards
Thomas

>
> And you will find a lot of hits. The last one is even documented as
> being "video.brightness_switch_enabled" in the main kernel-parameters.txt
> as well as separately:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/kernel-parameters.txt#n39
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/kernel-parameters.txt#n7152
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/firmware-guide/acpi/video_extension.rst#n118
>
> https://wiki.archlinux.org/title/Lenovo_ThinkPad_X1_Carbon#Brightness_control
>
> If you rename this module then peoples config will break for
> a whole lot of users.
>
> So lets not do that and lets rename the new module which is causing
> the conflict in the first place instead.
>
> Regards,
>
> Hans
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)