Re: [PATCH] Topcliff PHUB: Generate PacketHub driver

From: Masayuki Ohtake
Date: Tue Jun 15 2010 - 08:12:28 EST

Hi Arnd,

Thank you for your comments.
I can understand your intention.
I misunderstood about Kconfig behavior.


----- Original Message -----
From: "Arnd Bergmann" <arnd@xxxxxxxx>
To: "Masayuki Ohtake" <masa-korg@xxxxxxxxxxxxxxx>
Cc: "Alan Cox" <alan@xxxxxxxxxxxxxxxxxxx>; "LKML" <linux-kernel@xxxxxxxxxxxxxxx>; "Andrew"
<andrew.chih.howe.khor@xxxxxxxxx>; "Intel OTC" <joel.clark@xxxxxxxxx>; "Wang, Qi" <>; "Wang, Yong Y"
Sent: Tuesday, June 15, 2010 7:42 PM
Subject: Re: [PATCH] Topcliff PHUB: Generate PacketHub driver

> On Tuesday 15 June 2010, Masayuki Ohtake wrote:
> > >This should not be necessary. Just use CONFIG_PCH_CAN_PCLK_50MHZ directly
> > >in the code instead of the extra PCH_CAN_PCLK_50MHZ macro.
> >
> > I have a question. I show the above reason.
> > In case CAN is integrated as MODULE, macro name is CONFIG_PCH_CAN_PCLK_50MHZ_MODULE.
> > On the other hand, integrated as built-in, CONFIG_PCH_CAN_PCLK_50MHZ.
> > To prevent PHUB source code from integrated as MODULE or BUILT-IN,
> > we re-define macro name in Makefile.
> >
> > If use CONFIG_PCH_CAN_PCLK_50MHZ directly in the source code,
> > in case buit-in, behavior is not correct.
> > But in case module, behavior is not correct.
> I don't understand the problem, because you have the definition
> config PCH_CAN_PCLK_50MHZ
> bool "CAN PCLK 50MHz"
> depends on PCH_PHUB
> which is 'bool', not 'tristate', so it can never be a module.
> If you are referring to a dependency on the CAN code that is
> not part of this patch, you can express this as
> config PCH_CAN_PCLK_50MHZ
> bool "CAN PCLK 50MHz"
> depends on PCH_PHUB || CAN != "n"
> This will leave CONFIG_PCH_CAN_PCLK_50MHZ as bool and let it only
> get enabled if CONFIG_CAN is either "y" or "m".
> Does that answer your question?
> Arnd

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