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From:   Ondrej Zary <linux@rainbow-software.org>
To:     alsa-devel@alsa-project.org
Subject: Re: [alsa-devel] ALSA: nm256: Fine-tuning for three function implementations
Date:   Tue, 28 Nov 2017 13:33:14 +0100
User-Agent: KMail/1.9.10 (enterprise35 0.20100827.1168748)
Cc:     SF Markus Elfring <elfring@users.sourceforge.net>,
        Takashi Iwai <tiwai@suse.de>,
        Arvind Yadav <arvind.yadav.cs@gmail.com>,
        Takashi Sakamoto <o-takashi@sakamocchi.jp>,
        kernel-janitors@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
References: <d98a2685-ddf9-1cba-839a-d12c5ff8d3ba@users.sourceforge.net> <s5hbmjmluba.wl-tiwai@suse.de> <2cbef557-5f89-c630-e108-14ef2ce6b41a@users.sourceforge.net>
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On Tuesday 28 November 2017, SF Markus Elfring wrote:
> >>>> There is a general source code transformation pattern involved.
> >>>> So I find that it is systematic.
> >>>>
> >>>> But I did not dare to develop a script variant for the semantic patch
> >>>> language (Coccinelle software) which can handle all special use cases
> >>>> as a few of them are already demonstrated in this tiny patch series.
> >>>
> >>> Then you're doing everything by hands,
> >>
> >> I am navigating through possible changes around the pattern
> >> =E2=80=9CUse common error handling code=E2=80=9D mostly manually so fa=
r.
> >>
> >>> and can be wrong
> >>
> >> Such a possibility remains as usual.
> >
> > "As usual" doesn't suffice.
>
> There can be additional means be used to reduce the probability
> of undesired side effects.
>
> > It must be "almost perfect" for such a code refactoring.
>
> Can you get the impression that the shown transformation patterns were
> correctly applied for the source file =E2=80=9Csound/pci/nm256/nm256.c=E2=
=80=9D?

Have you tested the driver? Probably not. Please don't "improve" working=20
drivers unless you have the hardware to test your changes. Patches like thi=
s=20
are known to cause regressions. If the hardware is rare (like the NM256), t=
he=20
regression can hit years later when someone with such HW upgrades distro=20
(e.g. Debian stable).

=2D-=20
Ondrej Zary

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