linux-kernel - Re: [PATCH linux-next v5 1/1] spi: imx: dynamic burst length adjust for PIO mode

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Message-ID: <20170818104500.ixuiy7ghvyuavbdh@pengutronix.de>
Date:   Fri, 18 Aug 2017 12:45:01 +0200
From:   Oleksij Rempel <ore@...gutronix.de>
To:     Jiada Wang <jiada_wang@...tor.com>
Cc:     broonie@...nel.org, s.hauer@...gutronix.de,
        linux-spi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH linux-next v5 1/1] spi: imx: dynamic burst length adjust
 for PIO mode

On Thu, Aug 10, 2017 at 01:50:08PM +0900, Jiada Wang wrote:
> 
> previously burst length (BURST_LENGTH) is always set to equal
> to bits_per_word, causes a 10us gap between each word in
> transfer, which significantly affects performance.
> 
> This patch uses 32 bits transfer to simulate lower bits transfer,
> and adjusts burst length runtimely to use biggeest burst length
> as possible to reduce the gaps in transfer for PIO mode.
> 
> Signed-off-by: Jiada Wang <jiada_wang@...tor.com>

Tested-by: Oleksij Rempel <o.rempel@...gutronix.de>

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