Thomas Zimmermann <tzimmermann@xxxxxxx> writes:
> Hi
>
> Am 11.09.23 um 22:52 schrieb Arnd Bergmann:
>> From: Arnd Bergmann <arnd@xxxxxxxx>
>>
>> As a result of the recent Kconfig reworks, the default settings for the
>> framebuffer interfaces changed in unexpected ways:
>>
>> Configurations that leave CONFIG_FB disabled but use DRM now get
>> DRM_FBDEV_EMULATION by default. This also turns on the deprecated /dev/fb
>> device nodes for machines that don't actually want it.
>>
>> In turn, configurations that previously had DRM_FBDEV_EMULATION enabled
>> now only get the /dev/fb front-end but not the more useful framebuffer
>> console, which is not selected any more.
>>
>> We had previously decided that any combination of the three frontends
>> (FB_DEVICE, FRAMEBUFFER_CONSOLE and LOGO) should be selectable, but the
>> new default settings mean that a lot of defconfig files would have to
>> get adapted.
>>
>> Change the defaults back to what they were in Linux 6.5:
>>
>> - Leave DRM_FBDEV_EMULATION turned off unless CONFIG_FB
>> is enabled. Previously this was a hard dependency but now the two are
>> independent. However, configurations that enable CONFIG_FB probably
>> also want to keep the emulation for DRM, while those without FB
>> presumably did that intentionally in the past.
>>
>> - Leave FB_DEVICE turned off for FB=n. Following the same
>> logic, the deprecated option should not automatically get enabled
>> here, most users that had FB turned off in the past do not want it,
>> even if they want the console
>>
>> - Turn the FRAMEBUFFER_CONSOLE option on if
>> DRM_FBDEV_EMULATION is set to avoid having to change defconfig
>> files that relied on it being selected unconditionally in the past.
>> This also makes sense since both LOGO and FB_DEVICE are now disabled
>> by default for builds without CONFIG_FB, but DRM_FBDEV_EMULATION
>> would make no sense if all three are disabled.
>>
>> Fixes: a5ae331edb02b ("drm: Drop select FRAMEBUFFER_CONSOLE for DRM_FBDEV_EMULATION")
>> Fixes: 701d2054fa317 ("fbdev: Make support for userspace interfaces configurable")
>> Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
>
Pushed to drm-misc (drm-misc-fixes). Thanks!
--
Best regards,
Javier Martinez Canillas
Core Platforms
Red Hat
