Messages in this thread | | | Date | Fri, 30 Jun 2023 14:41:48 +0200 | Subject | Re: [PATCH 0/2] Allow disabling all native fbdev drivers and only keeping DRM emulation | From | Thomas Zimmermann <> |
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Hi
Am 30.06.23 um 14:33 schrieb Javier Martinez Canillas: > Thomas Zimmermann <tzimmermann@suse.de> writes: > > Hello Thomas, > > Thanks a lot for your review. > >> Hi Javier >> >> Am 30.06.23 um 00:51 schrieb Javier Martinez Canillas: >>> This patch series splits the fbdev core support in two different Kconfig >>> symbols: FB and FB_CORE. The motivation for this is to allow CONFIG_FB to >>> be disabled, while still having the the core fbdev support needed for the >>> CONFIG_DRM_FBDEV_EMULATION to be enabled. The motivation is automatically >>> disabling all fbdev drivers instead of having to be disabled individually. >>> >>> The reason for doing this is that now with simpledrm, there's no need for >>> the legacy fbdev (e.g: efifb or vesafb) drivers anymore and many distros >>> now disable them. But it would simplify the config a lot fo have a single >>> Kconfig symbol to disable all fbdev drivers. >> >> I still don't get the point of this change. We've disabled the fbdev >> drivers once. And they are off now and remain off. >> > > Yes, but doing that means you have a bunch of these in your kernel config: > > # > # Frame buffer hardware drivers > # > # CONFIG_FB_CIRRUS is not set > # CONFIG_FB_PM2 is not set > # CONFIG_FB_ARMCLCD is not set > ... > > I don't know how the kernel configuration management for the OpenSUSE > kernel package works, but at least in Fedora this translates to needing to > have a lot of explicit disable configurations in the form of: > > $ cat redhat/configs/common/generic/CONFIG_FB_CIRRUS > # CONFIG_FB_CIRRUS is not set > > $ ls redhat/configs/common/generic/CONFIG_FB_* | wc -l > 61 > > I want to get rid of all those and the goal of this series is to reduce > that configuration to only: > > $ cat redhat/configs/common/generic/CONFIG_FB > # CONFIG_FB is not set > > $ cat redhat/configs/common/generic/CONFIG_FB_CORE > CONFIG_FB_CORE=y
We have these 'is not set' lines on our kernel configs, but I don't think they bother anyone too much.
Well, thanks for explaining. At least I now see why you want to do this change.
> >> The patchset now introduces FB_CORE, which just adds more options. But >> you're not reducing the code or compile time or any thing similar. >> > > No need for any redhat/configs/common/generic/CONFIG_FB_* because those > don't need to be explicitly disabled anymore since CONFIG_FB isn't set. > > And the "Frame buffer hardware drivers" section in the .config goes away. > > So it is a configuration simplification even when you can achieve the same > with the existing Kconfig symbols. > >> I'd like to suggest a change to these patches: rather then making FB and >> DRM_FBDEV_EMULATION depend on FB_CORE, make them select FB_CORE. That >> will allow the DRM subsystem to enable framebuffer emulation >> independently from framebuffer devices. If either has been set, the >> fbdev core will be selected. >> > > Yes, I guess that making it a non user-visible option makes sense. I'm > just wary of using select because I've bitten in the past by circular > dependencies when other symbol depends on it. > > But I'm OK with that change and will do in v2.
Great, thanks.
Best regards Thomas
> >> Best regards >> Thomas >> >
-- 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) [unhandled content-type:application/pgp-signature] | |