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Date:   Tue, 29 Jan 2019 16:05:49 +0100
From:   Alexandre Belloni <alexandre.belloni@bootlin.com>
To:     Jonas Bonn <jonas@norrbonn.se>
Cc:     Nicolas.Ferre@microchip.com, linux-kernel@vger.kernel.org,
        broonie@kernel.org, Ludovic.Desroches@microchip.com,
        linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Tudor.Ambarus@microchip.com
Subject: Re: [PATCH v4 2/2] spi-atmel: support inter-word delay
Message-ID: <20190129150549.GA19959@piout.net>
References: <20190129083844.20572-1-jonas@norrbonn.se>
 <20190129083844.20572-3-jonas@norrbonn.se>
 <995b3885-254b-7932-8d05-77271a2c070d@microchip.com>
 <7a6efd1a-5920-60e5-bc68-dfbe6866e522@norrbonn.se>
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Hi,

On 29/01/2019 15:56:31+0100, Jonas Bonn wrote:
> On 29/01/2019 15:27, Nicolas.Ferre@microchip.com wrote:
> > On 29/01/2019 at 09:38, Jonas Bonn wrote:
> > > 
> > > +	/* DLYBCT adds delays between words.  This is useful for slow devices
> > > +	 * that need a bit of time to setup the next transfer.
> > > +	 */
> > > +	if (spi->word_delay_us) {
> > 
> > Well...
> > 
> > > +		csr |= SPI_BF(DLYBCT,
> > > +			clamp_t(u8,
> > > +				(as->spi_clk/1000000*spi->word_delay_us)>>5,
> > > +				1, 255));
> > 
> > ... why not simplifying to:
> > +				0, 255));
> > and remove the test altogether, after all?
> 
> Hmm... that seemed too easy!  This started out as something else and looking
> at it now I think even the clamp_t() is unnecessary.  The value is already
> 0-255 and the way SPI_BF works any overflow is already truncated...  I'll
> rework this and resubmit once I get some feedback on the word_delay_us bits.
> 

While at it, note that you need to add spaces around the operators.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com