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Date:   Tue, 13 Feb 2018 20:15:09 +0100
From:   Willy Tarreau <w@1wt.eu>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Robert Abel <rabel@robertabel.eu>
Subject: Re: [PATCH 1/3] auxdisplay: charlcd: fix hex literal ranges for
 graphics command
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On Tue, Feb 13, 2018 at 03:36:45PM +0200, Andy Shevchenko wrote:
> On Sat, Feb 10, 2018 at 11:41 AM, Miguel Ojeda
> <miguel.ojeda.sandonis@gmail.com> wrote:
> > On Sat, Feb 10, 2018 at 10:20 AM, Willy Tarreau <w@1wt.eu> wrote:
> >> On Sat, Feb 10, 2018 at 09:58:44AM +0100, Miguel Ojeda wrote:
> >>> On Sat, Feb 10, 2018 at 12:50 AM, Robert Abel <rabel@robertabel.eu> wrote:
> 
> >>> >                         shift ^= 4;
> >>> >                         if (*esc >= '0' && *esc <= '9') {
> >>> >                                 value |= (*esc - '0') << shift;
> >>> > -                       } else if (*esc >= 'A' && *esc <= 'Z') {
> >>> > +                       } else if (*esc >= 'A' && *esc <= 'F') {
> >>> >                                 value |= (*esc - 'A' + 10) << shift;
> >>> > -                       } else if (*esc >= 'a' && *esc <= 'z') {
> >>> > +                       } else if (*esc >= 'a' && *esc <= 'f') {
> >>>
> >>> Willy, Geert: this seems obvious, but do you know if the broader range
> >>> was intended for some reason?
> >>
> >> No, I think it was simply a brain fart from me 14 years ago, as I can
> >> find it as well in the original 0.9.0 patch for kernel 2.4!
> 
> I understand that we have a huge and hopefully nice library in the
> kernel, but the question still the same, what prevents a developer or
> maintainer to look at it from time to time?

It's always the same, nobody knows that some code appeared somewhere to
solve some problem they already solved a long time ago and that they are
not even aware of anymore. That's why code cleanups like this session are
useful.

> For, I dare to say, ages we have hex_to_bin() and hex2bin().
> Can we use it?

I definitely think so after taking a quick look at hex2bin().

Thanks!
Willy