From: marex@denx.de (Marek Vasut)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 08/10 RESEND] spi: Add DMA support into SPI driver
Date: Thu, 2 Aug 2012 17:00:42 +0200 [thread overview]
Message-ID: <201208021700.43159.marex@denx.de> (raw)
In-Reply-To: <20120801203448.GX4483@opensource.wolfsonmicro.com>
Dear Mark Brown,
> On Mon, Jul 23, 2012 at 10:40:50PM +0200, Marek Vasut wrote:
> > + /*
> > + * Small blocks can be transfered via PIO.
> > + * Measured by empiric means:
> > + *
> > + * dd if=/dev/mtdblock0 of=/dev/null bs=1024k count=1
> > + *
> > + * DMA only: 2.164808 seconds, 473.0KB/s
> > + * Combined: 1.676276 seconds, 610.9KB/s
> > + */
>
> I've seen other devices end up using the FIFO length as the decision
> point here which makes intuitive sense to me unless the FIFO is
> extremely deep.
Yep, that's all good. This device has not too deep FIFO, but the reason I chose
not to go that way is because the DMA allocations have some overhead too and
this values seemed to be the best.
> Not reviewed this properly yet but it looks OK from a first read
> through.
Thanks!
Best regards,
Marek Vasut
next prev parent reply other threads:[~2012-08-02 15:00 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-23 20:40 [PATCH 00/10 V2] MXS SPI driver Marek Vasut
2012-07-23 20:40 ` [PATCH 01/10 RESEND] mmc: spi: Move SSP register definitions into separate file Marek Vasut
2012-07-23 20:40 ` [PATCH 02/10 RESEND] mmc: spi: Rename IMX2[38]_MMC to IMX2[38]_SSP Marek Vasut
2012-07-23 20:40 ` [PATCH 03/10 V2] mmc: spi: Add necessary bits into mxs-spi.h Marek Vasut
2012-07-23 20:40 ` [PATCH 04/10 RESEND] mmc: spi: Pull out parts shared between MMC and SPI Marek Vasut
2012-07-23 20:40 ` [PATCH 05/10 V2] mmc: spi: Pull out the SSP clock configuration function Marek Vasut
2012-07-23 20:40 ` [PATCH 06/10 V2] spi: Add SPI driver for mx233/mx28 Marek Vasut
2012-08-01 20:31 ` Mark Brown
2012-08-02 14:58 ` Marek Vasut
2012-08-02 16:00 ` Mark Brown
2012-08-02 16:03 ` Marek Vasut
2012-08-03 1:29 ` Shawn Guo
2012-08-03 13:38 ` Thomas Petazzoni
2012-08-03 13:46 ` Fabio Estevam
2012-08-03 13:49 ` Marek Vasut
2012-08-03 14:00 ` Marek Vasut
2012-07-23 20:40 ` [PATCH 07/10 RESEND] mmc: spi: Pull out common DMA parts from MXS MMC Marek Vasut
2012-07-23 20:40 ` [PATCH 08/10 RESEND] spi: Add DMA support into SPI driver Marek Vasut
2012-08-01 20:34 ` Mark Brown
2012-08-02 15:00 ` Marek Vasut [this message]
2012-07-23 20:40 ` [PATCH 09/10 RESEND] spi: Add SSP/SPI device tree documentation Marek Vasut
2012-07-24 18:15 ` Sergei Shtylyov
2012-07-24 19:43 ` Marek Vasut
2012-07-28 11:40 ` Shawn Guo
2012-07-28 11:42 ` Marek Vasut
2012-07-23 20:40 ` [PATCH 10/10 RESEND] ARM: mx28: Add SPI pinmux into imx28.dtsi Marek Vasut
2012-07-24 9:25 ` [PATCH 00/10 V2] MXS SPI driver Attila Kinali
2012-08-03 14:30 ` [PATCH] SPI: MXS: Allow to pass the SPI master bus number from the device tree Maxime Ripard
2012-08-03 14:43 ` Shawn Guo
2012-08-03 16:27 ` Maxime Ripard
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