Re: [PATCH 08/14] zram: check that backends array has at least one backend

[Sergey Senozhatsky]

On (24/05/05 14:13), Sergey Senozhatsky wrote:
> On (24/05/05 13:39), Sergey Senozhatsky wrote:
> [..]
> > > I guess just pick one if none were selected.
> 
> How do I pick one if none were selected? Does Kconfig support
> something like that?

This triggers Kconfig error:

config ZRAM_EMPTY_BACKENDS_FIXUP
       bool
       depends on ZRAM && !ZRAM_BACKEND_LZO && !ZRAM_BACKEND_LZ4 && \
               !ZRAM_BACKEND_LZ4HC && !ZRAM_BACKEND_ZSTD && \
               !ZRAM_BACKEND_DEFLATE
       select ZRAM_BACKEND_LZO


drivers/block/zram/Kconfig:17:error: recursive dependency detected!
drivers/block/zram/Kconfig:17:  symbol ZRAM_BACKEND_LZO is selected by ZRAM_EMPTY_BACKENDS_FIXUP
drivers/block/zram/Kconfig:52:  symbol ZRAM_EMPTY_BACKENDS_FIXUP depends on ZRAM_BACKEND_LZO


I'm a little surprised by this - EMPTY_BACKENDS_FIXUP does not depend
on ZRAM_BACKEND_LZO, it depends on NOT ZRAM_BACKEND_LZO.

Let me Cc linux-kbuild. Kbuild folks, how do I workaround this?