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In-Reply-To: <a73b3ec0-5abb-ddfd-414b-b9807f05413e@linux.intel.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Fri, 8 Jul 2022 17:25:20 +0200
Message-ID: <CAHp75Vd4D0KF7ik+aMOwv-+bofWja_tDe4YUmihQBF+RiHZTmA@mail.gmail.com>
Subject: Re: [PATCH 1/2] lib/string_helpers: Introduce strsplit_u32()
To:     =?UTF-8?Q?P=C3=A9ter_Ujfalusi?= <peter.ujfalusi@linux.intel.com>
Cc:     Cezary Rojewski <cezary.rojewski@intel.com>,
        Andy Shevchenko <andy@kernel.org>,
        Mark Brown <broonie@kernel.org>,
        ALSA Development Mailing List <alsa-devel@alsa-project.org>,
        Takashi Iwai <tiwai@suse.com>,
        Jaroslav Kysela <perex@perex.cz>,
        amadeuszx.slawinski@linux.intel.com,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
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        Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
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        Bard Liao <yung-chuan.liao@linux.intel.com>
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On Fri, Jul 8, 2022 at 2:34 PM P=C3=A9ter Ujfalusi
<peter.ujfalusi@linux.intel.com> wrote:
> On 08/07/2022 15:30, Andy Shevchenko wrote:
> > On Fri, Jul 08, 2022 at 02:13:14PM +0200, Cezary Rojewski wrote:

...

> > It seems you are missing the (1). The code has checks for the case wher=
e you
> > can do get number upfront, it would just require two passes, but it's n=
othing
> > in comparison of heave realloc().
> >
> >   unsigned int *tokens;
> >   char *p;
> >   int num;
> >
> >   p =3D get_options(str, 0, &num);
> >   if (num =3D=3D 0)
> >       // No numbers in the string!
> >
> >   tokens =3D kcalloc(num + 1, sizeof(*tokens), GFP_KERNEL);
> >   if (!tokens)
> >       return -ENOMEM;
> >
> >   p =3D get_oprions(str, num, &tokens);
> >   if (*p)
> >       // String was parsed only partially!
> >       // assuming it's not a fatal error
> >
> >   return tokens;

> This diff is tested and works:

Thanks, Peter!

But at least you can memove() to avoid second allocation.
ideally to refactor that the result of get_options is consumed as is
(it may be casted to struct tokens { int n; u32 v[]; })

...

> Could be made nicer with some brain work put to it, we need strict u32 wi=
thin the IPC message for the array...

True, it needs to be thought through. But I guess you got the idea of
how to use existing library routines.

--=20
With Best Regards,
Andy Shevchenko