Message-ID: <5341C22A.1050907@lwfinger.net>
Date: Sun, 06 Apr 2014 16:07:54 -0500
From: Larry Finger <Larry.Finger@lwfinger.net>
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To: Paul Bolle <pebolle@tiscali.nl>, Randy Dunlap <rdunlap@infradead.org>
CC: LKML <linux-kernel@vger.kernel.org>
Subject: Re: Kconfig circular dependency question
References: <5341AFC7.1070001@lwfinger.net> <5341B999.3050206@infradead.org> <1396817575.4886.23.camel@x220>
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On 04/06/2014 03:52 PM, Paul Bolle wrote:
> On Sun, 2014-04-06 at 13:31 -0700, Randy Dunlap wrote:
>> and/or changing MOUSE_APPLETOUCH to depend on USB instead of select it?
>
> MOUSE_APPLETOUCH selects USB and depends on USB_ARCH_HAS_HCD. That's
> actually quite a common pattern.
>
> But what is the purpose of USB_ARCH_HAS_HCD? It is set by default if
> USB_SUPPORT is set. And USB depends on it, but since USB also depends on
> USB_SUPPORT that seems superfluous.
>
> My slow day continues, because I find this hard to grok.

As you have seen in my reply to Randy, this appears to arise from violating one 
of the edicts of Linus that says that no configuration variable should select a 
subsystem. Of course, one could argue that RFKILL is also a subsystem, and that 
R8723AU should depend on it rather that selecting it.

My day also seems to be slowing. :)

Larry


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