Date: Tue, 7 Jul 2009 13:30:54 -0700 (PDT)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Krzysztof Helt <krzysztof.h1@poczta.fm>
cc: Linux-fbdev-devel <linux-fbdev-devel@lists.sourceforge.net>,
       linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
       a.p.zijlstra@chello.nl, rjw@sisk.pl, stable@kernel.org
Subject: Re: matroxfb: fix regression with uninitalized fb_info->mm_lock
 mutex (second head)
In-Reply-To: <20090707223413.d56c6a7f.krzysztof.h1@poczta.fm>
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On Tue, 7 Jul 2009, Krzysztof Helt wrote:
> 
> Remove redundant locking by the mm_lock mutex before a second head of matrox 
> framebuffer is registered.

Why do you write misleading commentary like this.

> +/*
> + * This function is called before the register_framebuffer so
> + * no locking is needed.
> + */

Or this?

It's not about "needed". The locking is not only not needed, it would be 
BUGGY.

And it's not "redundant". That implies that it's done somewhere else. It's 
more than "not needed" - it would be actively buggy to lock things there.

I really don't like how you're approaching this. You're ignoring the real 
issues I ask you, you're writing misleading comments and commit messages, 
and the end result is fragile code. I still don't understand why you 
insist on initializing those things late, which is the primary problem 
here.

		Linus
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