From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Robert Hancock <hancockr@shaw.ca>
Subject: Re: NAK new drivers without proper power management?
Date: Sun, 11 Feb 2007 01:44:16 +0100
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Cc: nigel@nigel.suspend2.net, linux-kernel <linux-kernel@vger.kernel.org>,
       Pavel Machek <pavel@ucw.cz>
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On Sunday, 11 February 2007 00:20, Robert Hancock wrote:
> Nigel Cunningham wrote:
> > If your device requires power management, and you know it requires power
> > management, why not just implement power management? Doing -ENOSYS
> > instead is like saying -ESPAMMEBECAUSEIMLAZY.
> > 
> > Let me put it another way: People keep talking about Linux being ready
> > for the desktop. To me at least (but I dare say for lots of other people
> > too), being ready for the desktop means that things just work, without
> > having to recompile kernels or bug driver authors or wait twelve
> > months. 
> > 
> > And it means that doing a bare minimum isn't enough. We keep claiming
> > that Open Source is better than Proprietary software. If we accept
> > half-pie jobs of implementing support for anything - driver power
> > management support or hibernation support or whatever - as 'good
> > enough', we're undercutting that argument. Linux's power management
> > support should - as far as we're able - be at least as good as that
> > other operating system's and preferably way, way better.
> > 
> > -ENOSYS is just not acceptable.
> 
> Well, it's probably more acceptable than silently doing nothing and the 
> device failing or locking up the machine on resume, but I couldn't agree 
> more that it's not what we want to be encouraging. Perfect may be the 
> enemy of the good, but "works except no power management" is hardly what 
> I would call good these days, more like pretty sloppy..

I think there are situations in which it can be justified, like:
- The driver is not entirely finished, but we want to merge it early, because
of many potential users,
- The driver has only a few users who aren't interested in the suspend/resume
functionality,
- The device is undocumented and we don't know how to make it handle the
suspend/resume (we may learn that in the future or not).

For this reason I 100% agree that we should _encourage_ implementing .suspend
and .resume, but we should not make it an unbreakable rule cast in stone.

Greetings,
Rafael


-- 
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