linux-kernel - Re: [PATCH] asm/io: Correct output operand specification of the MMIO write* routines

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Message-ID: <alpine.LSU.2.21.1904181203170.8064@wotan.suse.de>
Date:   Thu, 18 Apr 2019 12:16:47 +0000 (UTC)
From:   Michael Matz <matz@...e.de>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
cc:     Borislav Petkov <bp@...en8.de>, x86-ml <x86@...nel.org>,
        lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] asm/io: Correct output operand specification of the MMIO
 write* routines

Hi,

On Wed, 17 Apr 2019, Linus Torvalds wrote:

> So I see no upside to changing it.

As long as the memory clobber stays (and it can't be removed in the 
general case, as you say) the change has no practical effect.

<outsider>
It does have a psychological upside, though: people won't continue to 
wonder why the asm doesn't precisely specify what it does, and instead 
only declares a memory-read while clearly being a memory write.  
Normally, with asms, leaving nothing to wonder about is a good thing.
</outsider>

Ciao,
Michael.