Re: [PATCH] powerpc: Use shared font data

From: Michael Ellerman
Date: Wed Aug 02 2023 - 08:19:53 EST


"Dr. David Alan Gilbert" <linux@xxxxxxxxxxx> writes:
> * Michael Ellerman (mpe@xxxxxxxxxxxxxx) wrote:
>> linux@xxxxxxxxxxx writes:
>> > From: "Dr. David Alan Gilbert" <linux@xxxxxxxxxxx>
>> >
>> > PowerPC has a 'btext' font used for the console which is almost identical
>> > to the shared font_sun8x16, so use it rather than duplicating the data.
>> >
>> > They were actually identical until about a decade ago when
>> > commit bcfbeecea11c ("drivers: console: font_: Change a glyph from
>> > "broken bar" to "vertical line"")
>> >
>> > which changed the | in the shared font to be a solid
>> > bar rather than a broken bar. That's the only difference.
>> >
>> > This was originally spotted by PMD which noticed that sparc does
>>
>> PMD means "Page Middle Directory" to most Linux folks, I assume that's
>> not what you meant :)
>
> Ah, any good TLA is ripe for reuse:
> https://pmd.github.io/pmd/pmd_userdocs_cpd.html

Thanks.

Unfortunately this patch causes a warning:

WARNING: unmet direct dependencies detected for FONT_SUN8x16
Depends on [n]: FONT_SUPPORT [=y] && FRAMEBUFFER_CONSOLE [=y] && (!SPARC && FONTS [=n] || SPARC)
Selected by [y]:
- BOOTX_TEXT [=y] && PPC_BOOK3S [=y]

And breaks allmodconfig with:

ld: arch/powerpc/kernel/btext.o:(.toc+0x0): undefined reference to `font_sun_8x16'
make[3]: *** [../scripts/Makefile.vmlinux:36: vmlinux] Error 1

I guess the Kconfig logic needs some more work.

cheers