Subject: Re: NAK new drivers without proper power management?
From: Nigel Cunningham <nigel@nigel.suspend2.net>
Reply-To: nigel@nigel.suspend2.net
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Pavel Machek <pavel@ucw.cz>, "Rafael J. Wysocki" <rjw@sisk.pl>,
       Arjan van de Ven <arjan@infradead.org>,
       LKML <linux-kernel@vger.kernel.org>
In-Reply-To: <Pine.LNX.4.62.0702121653160.2928@pademelon.sonytel.be>
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Date: Tue, 13 Feb 2007 07:38:08 +1100
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Hi.

On Mon, 2007-02-12 at 16:57 +0100, Geert Uytterhoeven wrote:
> On Mon, 12 Feb 2007, Pavel Machek wrote:
> > > Can't the upper layer just assume -ENOSYS if .resume/.suspend is NULL?
> > > It's nicer if you don't have to implement dummy functions at all.
> > 
> > Unfortunately, drivers currently assume "NULL == nothing is needed",
> > so we'd have t do big search & replace... 
> 
> Which means you also cannot easily keep track of which driver supports
> suspend/resume and which doesn't, as there will always be drivers where a
> missing suspend/resume function is correct.
> 
> Wouldn't it be more sensible to have
> 
>     .suspend = suspend_nothing_to_do
> 
> instead, and reserve NULL for `not yet implemented'?

Agreed.

Regards,

Nigel

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