From: Javier Martinez Canillas <javierm@redhat.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
Sam Ravnborg <sam@ravnborg.org>, Peter Jones <pjones@redhat.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
DRI Development <dri-devel@lists.freedesktop.org>,
Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
Hans de Goede <hdegoede@redhat.com>,
Ilya Trukhanov <lahvuun@gmail.com>,
Thorsten Leemhuis <regressions@leemhuis.info>,
Borislav Petkov <bp@suse.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v2] fbdev: Prevent probing generic drivers if a FB is already registered
Date: Tue, 16 Nov 2021 11:01:38 +0100 [thread overview]
Message-ID: <7cbadb2a-b6e9-f264-9d95-b76c7071af27@redhat.com> (raw)
In-Reply-To: <CAMuHMdWotEN1TtTr7douLkQPkpXE-rQgamM3GOYO1XNHbUiguw@mail.gmail.com>
Hello Geert,
On 11/16/21 10:43, Geert Uytterhoeven wrote:
[snip]
>>
>> So this is already a fragile solution and $SUBJECT doesn't make things worse
>> IMO. Since not having something like this can lead to issues as reported by:
>>
>> https://lore.kernel.org/all/20211110200253.rfudkt3edbd3nsyj@lahvuun/
>>
>> We could probably do some smarter here by providing a function that checks
>> if the registered fbdev drivers matches the aperture base. But I'm unsure
>> if that's worth it. After all, fbdev drivers are likely to be disabled by
>> most distros soon now that we have the simpledrm driver.
>
> Checking the aperture base is what was done in all other cases of
> preventing generic (fbdev) drivers from stepping on specific drivers'
> toes...
>
Ok, I can re-spin the patch checking if the aperture ranges overlap. There's
an apertures_overlap() function in drivers/video/fbdev/core/fbmem.c that can
be exported for fbdev drivers to use.
Another option is to just say that DRM drivers should be built as a module if
the {efi,simple}fb driver are built-in.
Best regards,
--
Javier Martinez Canillas
Linux Engineering
Red Hat
next prev parent reply other threads:[~2021-11-16 10:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 11:11 [PATCH v2] fbdev: Prevent probing generic drivers if a FB is already registered Javier Martinez Canillas
2021-11-11 11:39 ` Greg Kroah-Hartman
2021-11-12 16:12 ` Daniel Vetter
2021-11-15 16:20 ` Geert Uytterhoeven
2021-11-16 9:30 ` Javier Martinez Canillas
2021-11-16 9:43 ` Geert Uytterhoeven
2021-11-16 10:01 ` Javier Martinez Canillas [this message]
2021-11-16 13:49 ` Javier Martinez Canillas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7cbadb2a-b6e9-f264-9d95-b76c7071af27@redhat.com \
--to=javierm@redhat.com \
--cc=bp@suse.de \
--cc=daniel.vetter@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=geert@linux-m68k.org \
--cc=gregkh@linuxfoundation.org \
--cc=hdegoede@redhat.com \
--cc=lahvuun@gmail.com \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pjones@redhat.com \
--cc=regressions@leemhuis.info \
--cc=sam@ravnborg.org \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).