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From: Andi Shyti <andi@etezian.org>
To: Mark Brown <broonie@kernel.org>
Cc: Andi Shyti <andi.shyti@samsung.com>,
	Kukjin Kim <kgene@kernel.org>,
	Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	Jaehoon Chung <jh80.chung@samsung.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-spi@vger.kernel.org,
	linux-kernel@vger.kernel.org, Andi Shyti <andi@etezian.org>
Subject: Re: [PATCH v2 5/5] spi: s3c64xx: use unsigned type for fifo handling variables
Date: Wed, 6 Jul 2016 00:01:21 +0900	[thread overview]
Message-ID: <20160705150121.GF1257@jack.zhora.eu> (raw)
In-Reply-To: <20160705145556.GD6247@sirena.org.uk>

Hi Mark,

> > The 'quirks' variable cannot ever be negative, therefore use u8
> > instead of int. The 8 bit size is given from the fact that
> > currently the quirks variable has very few statuses.
> > 
> > The rx_lvl_offset and tx_st_done store shift values, so that u8
> > is a proper size.
> > 
> > fifo_lvl_mask stores a series of masks, to be in we will keep the
> > 32 bit size.
> 
> What's the advantage of these changes?  This feels like microptimisation
> of something that shouldn't be a big performance issue and it's not
> always the case that the compiler does something more sensible with
> smaller or unsigned types.  I'm not saying don't do it, I'm just saying
> that it's not clear to me what the win is.

not much indeed. Just something that was a little bothering me
while I was reading through.

Please, feel free to drop it.

Thanks,
Andi

      reply	other threads:[~2016-07-05 15:01 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-28  2:41 [PATCH v2 0/5] s3c64xx: consider the case of a disconnected CS line and some code rework Andi Shyti
2016-06-28  2:41 ` [PATCH v2 1/5] spi: s3c64xx: group the CS signalling writes in a single function Andi Shyti
2016-06-28  2:41 ` [PATCH v2 2/5] spi: s3c64xx: consider the case when the CS line is not connected Andi Shyti
2016-06-30 12:15   ` Applied "spi: s3c64xx: consider the case when the CS line is not connected" to the spi tree Mark Brown
2016-06-28  2:41 ` [PATCH v2 3/5] spi: s3c64xx: do not configure the device twice Andi Shyti
2016-06-28  2:41 ` [PATCH v2 4/5] spi: s3c64xx: simplify if statement in prepare_transfer function Andi Shyti
2016-06-28  2:41 ` [PATCH v2 5/5] spi: s3c64xx: use unsigned type for fifo handling variables Andi Shyti
2016-07-05 14:55   ` Mark Brown
2016-07-05 15:01     ` Andi Shyti [this message]

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