Re: matroxfb: fix regression with uninitalized fb_info->mm_lockmutex (second head)

From: Linus Torvalds
Date: Tue Jul 07 2009 - 16:33:18 EST




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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