linux-kernel - Re: blink driver power saving

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Message-Id: <200707012329.52918.ak@suse.de>
Date:	Sun, 1 Jul 2007 23:29:52 +0200
From:	Andi Kleen <ak@...e.de>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Stephen Hemminger <shemminger@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: blink driver power saving

On Sunday 01 July 2007 20:07:21 Linus Torvalds wrote:
> 
> On Sun, 1 Jul 2007, Stephen Hemminger wrote:
> >
> > The blink driver wakes up every jiffies which wastes power unnecessarily.
> > Using a notifier gives same effect. Also add ability to unload module.
> 
> I really get the feeling this thing should be removed entirely. Wasting 
> power is the _least_ of its problems.

What is so bad with it? Note it's a debugging facility and used 
for kcrash kernels where the video output doesn't work. But they
normally only run a few minutes to dump the previous state to disk
and then reboot. 

> I'll apply the patch, but I wonder if I should also just mark it BROKEN in 
> the config file to make sure nobody enables it without realizing how bad 
> it is to do so.

Well I suspect it will not work anymore after Stephen's patch
(or rather try to blink redundantly after panic which is quite dumb) 
If that is your aim then it might be cleaner to remove it.

But then I don't think it hurts anybody.  It's main problem
is that it won't blink for people with USB keyboard.

-Andi
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