linux-kernel - Re: Kconfig circular dependency question

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5341C105.3060608@lwfinger.net>
Date:	Sun, 06 Apr 2014 16:03:01 -0500
From:	Larry Finger <Larry.Finger@...inger.net>
To:	Randy Dunlap <rdunlap@...radead.org>,
	LKML <linux-kernel@...r.kernel.org>
CC:	Paul Bolle <pebolle@...cali.nl>
Subject: Re: Kconfig circular dependency question

On 04/06/2014 03:31 PM, Randy Dunlap wrote:
> On 04/06/2014 12:49 PM, Larry Finger wrote:
>> A kernel build is reporting the following:
>>
>> net/rfkill/Kconfig:4:error: recursive dependency detected!
>> net/rfkill/Kconfig:4:   symbol RFKILL is selected by R8723AU
>> drivers/staging/rtl8723au/Kconfig:1:    symbol R8723AU depends on USB
>> drivers/usb/Kconfig:41: symbol USB is selected by MOUSE_APPLETOUCH
>> drivers/input/mouse/Kconfig:162:        symbol MOUSE_APPLETOUCH depends on INPUT
>> drivers/input/Kconfig:8:        symbol INPUT is selected by ACPI_CMPC
>> drivers/platform/x86/Kconfig:635:       symbol ACPI_CMPC depends on RFKILL
>>
>> What is the recommended way to avoid this circularity? Of course, R8723AU could select USB rather than depending on it, but that does not seem quite right.
>
> I don't know if it will fix the problem, but Linus has spoken (written)
> against selecting subsystems, like INPUT or USB.
>
> Does changing ACPI_CMPC to depend on INPUT instead of select INPUT
> help?
> and/or changing MOUSE_APPLETOUCH to depend on USB instead of select it?

This case seems to prove why Linus has so spoken!

Changing ACPI_CMPC to depend on INPUT does fix the build. Making the change to 
MOUSE_APPLETOUCH ends up getting a different recursive error.

Thanks for your suggestion. As I do not "own" the x86 platform drivers, I will 
have to post a patch to fix the ACPI_CMPC problem, but at least I know what to 
say in the commit message that adds the RFKILL selection to the R8723AU Kconfig.

Larry



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/