linux-kernel - Re: [PATCH v2 03/15] spi: Replace if-else-if by bitops and multiplications

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Message-ID: <ZK015fKTOK5wjck+@smile.fi.intel.com>
Date:   Tue, 11 Jul 2023 13:58:45 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Mark Brown <broonie@...nel.org>
Cc:     Cristian Ciocaltea <cristian.ciocaltea@...labora.com>,
        Yang Yingliang <yangyingliang@...wei.com>,
        Amit Kumar Mahapatra via Alsa-devel 
        <alsa-devel@...a-project.org>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Tharun Kumar P <tharunkumar.pasumarthi@...rochip.com>,
        Vijaya Krishna Nivarthi <quic_vnivarth@...cinc.com>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>, linux-spi@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-amlogic@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org, linux-arm-msm@...r.kernel.org,
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        Steven Rostedt <rostedt@...dmis.org>,
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        Richard Cochran <richardcochran@...il.com>
Subject: Re: [PATCH v2 03/15] spi: Replace if-else-if by bitops and
 multiplications

On Mon, Jul 10, 2023 at 05:56:59PM +0100, Mark Brown wrote:
> On Mon, Jul 10, 2023 at 06:49:20PM +0300, Andy Shevchenko wrote:
> 
> > -		if (xfer->bits_per_word <= 8)
> > -			maxsize = maxwords;
> > -		else if (xfer->bits_per_word <= 16)
> > -			maxsize = 2 * maxwords;
> > -		else
> > -			maxsize = 4 * maxwords;
> > -
> > +		maxsize = maxwords * roundup_pow_of_two(BITS_TO_BYTES(xfer->bits_per_word));
> 
> This will change the behaviour if bits_per_word is more than 32.  That
> is validated out elsewhere but I shouldn't have had to go around
> checking the code to confirm that this is the case.  This is the sort of
> thing that should be highlighted when doing this sort of edge case
> stylistic change.

Right, I have to add this into commit message of v3.

-- 
With Best Regards,
Andy Shevchenko