Re: [PATCH 00/17] fbdev: Remove FBINFO_DEFAULT and FBINFO_FLAG_DEFAULT flags

Thomas Zimmermann
2023-07-11T06:24:46Z

[-- Attachment #1.1: Type: text/plain, Size: 2076 bytes --]

Hi Sam

Am 10.07.23 um 19:19 schrieb Sam Ravnborg:
> Hi Thomas,
>
> On Mon, Jul 10, 2023 at 02:50:04PM +0200, Thomas Zimmermann wrote:
>> Remove the unused flags FBINFO_DEFAULT and FBINFO_FLAG_DEFAULT from
>> fbdev and drivers, as briefly discussed at [1]. Both flags were maybe
>> useful when fbdev had special handling for driver modules. With
>> commit 376b3ff54c9a ("fbdev: Nuke FBINFO_MODULE"), they are both 0
>> and have no further effect.
>>
>> Patches 1 to 7 remove FBINFO_DEFAULT from drivers. Patches 2 to 5
>> split this by the way the fb_info struct is being allocated. All flags
>> are cleared to zero during the allocation.
>>
>> Patches 8 to 16 do the same for FBINFO_FLAG_DEFAULT. Patch 8 fixes
>> an actual bug in how arch/sh uses the tokne for struct fb_videomode,
>> which is unrelated.
>>
>> Patch 17 removes both flag constants from <linux/fb.h>
>
> We have a few more flags that are unused - should they be nuked too?
> FBINFO_HWACCEL_FILLRECT
> FBINFO_HWACCEL_ROTATE
> FBINFO_HWACCEL_XPAN

It seems those are there for completeness. Nothing sets _ROTATE, the
others are simply never checked. According to the comments, some are
required, some are optional. I don't know what that means.

IIRC there were complains about performance when Daniel tried to remove
fbcon acceleration, so not all _HWACCEL_ flags are unneeded.

Leaving them in for reference/completeness might be an option; or not. I
have no strong feelings about those flags.

>
> Unused as in no references from fbdev/core/*
>
> I would rather see one series nuke all unused FBINFO flags in one go.
> Assuming my quick grep are right and the above can be dropped.

I would not want to extend this series. I'm removing _DEFAULT as it's
absolutely pointless and confusing.

Best regards
Thomas

>
> Sam

--
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)

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 840 bytes --]