build failure in linux-next: offb missing fb helpers

[Randy Dunlap]

Hi,

On 11/19/22 07:37, Michal Suchánek wrote:
> Hello,
> 
> On Sat, Nov 19, 2022 at 10:27:04PM +0900, Masahiro Yamada wrote:
>> On Sat, Nov 19, 2022 at 3:20 PM Randy Dunlap <rdunlap at infradead.org> wrote:
>>>
>>> Hi--
>>>
>>> [adding Masahiro-san]
>>>
>>>
>>> On 11/18/22 07:03, Michal Suchánek wrote:
>>>> Hello,
>>>>
>>>> I am seeing these errors:
>>>>
>>>> [ 3825s]   AR      built-in.a
>>>> [ 3827s]   AR      vmlinux.a
>>>> [ 3835s]   LD      vmlinux.o
>>>> [ 3835s]   OBJCOPY modules.builtin.modinfo
>>>> [ 3835s]   GEN     modules.builtin
>>>> [ 3835s]   GEN     .vmlinux.objs
>>>> [ 3848s]   MODPOST Module.symvers
>>>> [ 3848s]   CC      .vmlinux.export.o
>>>> [ 3849s]   UPD     include/generated/utsversion.h
>>>> [ 3849s]   CC      init/version-timestamp.o
>>>> [ 3849s]   LD      .tmp_vmlinux.btf
>>>> [ 3864s] ld: drivers/video/fbdev/offb.o:(.data.rel.ro+0x58): undefined
>>>> reference to `cfb_fillrect'
>>>> [ 3864s] ld: drivers/video/fbdev/offb.o:(.data.rel.ro+0x60): undefined
>>>> reference to `cfb_copyarea'
>>>> [ 3864s] ld: drivers/video/fbdev/offb.o:(.data.rel.ro+0x68): undefined
>>>> reference to `cfb_imageblit'
>>>>
>>>> cfb_fillrect is provided by drivers/video/fbdev/core/cfbfillrect.c
>>>>
>>>> It is compiled when CONFIG_FB_CFB_FILLRECT
>>>> drivers/video/fbdev/core/Makefile:obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
>>>>
>>>> drivers/video/fbdev/Makefile:obj-$(CONFIG_FB_OF)               += offb.o
>>>> is compiled when CONFIG_FB_OF
>>>>
>>>> It selects CONFIG_FB_CFB_FILLRECT
>>>> config FB_OF
>>>>         bool "Open Firmware frame buffer device support"
>>>>         depends on (FB = y) && PPC && (!PPC_PSERIES || PCI)
>>>>         select APERTURE_HELPERS
>>>>         select FB_CFB_FILLRECT
>>>>         select FB_CFB_COPYAREA
>>>>         select FB_CFB_IMAGEBLIT
>>>>         select FB_MACMODES
>>>>
>>>> The config has FB_OF built-in and FB_CFB_FILLRECT modular
>>>> config/ppc64le/vanilla:CONFIG_FB_CFB_FILLRECT=m
>>>> config/ppc64le/vanilla:CONFIG_FB_CFB_COPYAREA=m
>>>> config/ppc64le/vanilla:CONFIG_FB_CFB_IMAGEBLIT=m
>>>> config/ppc64le/vanilla:CONFIG_FB_OF=y
>>>>
>>>> It only depends on FB which mut be built-in for FB_OF
>>>> config FB_CFB_FILLRECT
>>>>         tristate
>>>>         depends on FB
>>>>
>>>> Is select in kconfig broken?
>>>>
>>>> Attachnig the config in question.
>>>
>>> The symbol info from xconfig says:
>>>
>>> Symbol: FB_CFB_FILLRECT [=m]
>>> Type : tristate
>>> Defined at drivers/video/fbdev/Kconfig:69
>>> Depends on: HAS_IOMEM [=y] && FB [=y]
>>> Selected by [m]:
>>> [deleted]
>>> - FB_OF [=y] && HAS_IOMEM [=y] && FB [=y]=y && PPC [=y] && (!PPC_PSERIES [=y] || PCI [=y]) && !DRM_OFDRM [=m]
>>>
>>> I don't see why the 'select' from (bool) FB_OF would leave FB_CFB_FILLRECT (and the others)
>>> as =m instead of =y.
>>>
>>> Hopefully Masahiro can shed some light on this.
>>>
>>> --
>>> ~Randy
>>
>>
>> The reason is shown in your paste of help message:
>>
>> "&& !DRM_OFDRM [=m]" downgrades it to "selected by m"
>>
>> To aid this particular case, the following will select
>> FB_CFB_FILLRECT=y.
>>
>>

Thanks again for your help.

>>
>>
>> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
>> index 66f36b69e8f3..2bcf8627819f 100644
>> --- a/drivers/video/fbdev/Kconfig
>> +++ b/drivers/video/fbdev/Kconfig
>> @@ -458,7 +458,7 @@ config FB_ATARI
>>  config FB_OF
>>         bool "Open Firmware frame buffer device support"
>>         depends on (FB = y) && PPC && (!PPC_PSERIES || PCI)
>> -       depends on !DRM_OFDRM
>> +       depends on DRM_OFDRM != y
>>         select APERTURE_HELPERS
>>         select FB_CFB_FILLRECT
>>         select FB_CFB_COPYAREA
> 
> Thanks for clarification.
> 
> This change fixess the config for me.


Thomas, is this change to DRM_OFDRM under FB_OF acceptable to you?


>> Or, perhaps "depends on DRM_OFDRM = n"
>> I do not know the intention of this dependency.
>>
>> Recommendation is to use "depends on" instead of "select" though.
>>
>>
>>
>> BTW, this is similar to what you asked before.
>>
>> https://lore.kernel.org/linux-kbuild/e1a6228d-1341-6264-d97a-e2bd52a65c82@infradead.org/
>>
>>
>> I tried to fix it in the past, but the issue was not as shallow as I
>> had expected.
>> I did not get around to revisiting this topic.
>>
>> https://patchwork.kernel.org/project/linux-kbuild/patch/1543216969-2227-1-git-send-email-yamada.masahiro@socionext.com/
>>

-- 
~Randy