From: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org> To: Mark Brown <broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> Cc: Fabio Estevam <fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org>, Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, Attila Kinali <attila-HB9FjVmMKa7tRgLqZ5aouw@public.gmane.org>, spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Chris Ball <cjb-2X9k7bc8m7Mdnm+yROfE0A@public.gmane.org>, Dong Aisheng <b29396-KZfg59tc24xl57MIdRCFDg@public.gmane.org>, Linux ARM kernel <linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org> Subject: Re: [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-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> 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 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
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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: 60+ 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 ` Marek Vasut [not found] ` <1343076052-27312-1-git-send-email-marex-ynQEQJNshbs@public.gmane.org> 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 ` 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 ` 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 ` 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 ` 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 ` Marek Vasut 2012-07-23 20:40 ` [PATCH 06/10 V2] spi: Add SPI driver for mx233/mx28 Marek Vasut 2012-07-23 20:40 ` Marek Vasut [not found] ` <1343076052-27312-7-git-send-email-marex-ynQEQJNshbs@public.gmane.org> 2012-08-01 20:31 ` Mark Brown 2012-08-01 20:31 ` Mark Brown [not found] ` <20120801203106.GW4483-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> 2012-08-02 14:58 ` Marek Vasut 2012-08-02 14:58 ` Marek Vasut [not found] ` <201208021658.38237.marex-ynQEQJNshbs@public.gmane.org> 2012-08-02 16:00 ` Mark Brown 2012-08-02 16:00 ` Mark Brown [not found] ` <20120802160016.GA4537-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> 2012-08-02 16:03 ` Marek Vasut 2012-08-02 16:03 ` Marek Vasut 2012-08-03 1:29 ` Shawn Guo 2012-08-03 1:29 ` Shawn Guo 2012-08-03 13:38 ` Thomas Petazzoni 2012-08-03 13:38 ` Thomas Petazzoni 2012-08-03 13:46 ` Fabio Estevam 2012-08-03 13:46 ` Fabio Estevam [not found] ` <CAOMZO5AQs1NzJBogcLPcKtY=QSaxpDmzUTvpfScY7P10FEoMJw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2012-08-03 13:49 ` Marek Vasut 2012-08-03 13:49 ` Marek Vasut 2012-08-03 14:00 ` 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 ` Marek Vasut 2012-07-23 20:40 ` [PATCH 08/10 RESEND] spi: Add DMA support into SPI driver Marek Vasut 2012-07-23 20:40 ` Marek Vasut [not found] ` <1343076052-27312-9-git-send-email-marex-ynQEQJNshbs@public.gmane.org> 2012-08-01 20:34 ` Mark Brown 2012-08-01 20:34 ` Mark Brown [not found] ` <20120801203448.GX4483-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> 2012-08-02 15:00 ` Marek Vasut [this message] 2012-08-02 15:00 ` Marek Vasut 2012-07-23 20:40 ` [PATCH 09/10 RESEND] spi: Add SSP/SPI device tree documentation Marek Vasut 2012-07-23 20:40 ` Marek Vasut 2012-07-24 18:15 ` Sergei Shtylyov 2012-07-24 18:15 ` Sergei Shtylyov [not found] ` <500EE64B.8080103-Igf4POYTYCDQT0dZR+AlfA@public.gmane.org> 2012-07-24 19:43 ` Marek Vasut 2012-07-24 19:43 ` Marek Vasut [not found] ` <201207242143.49038.marex-ynQEQJNshbs@public.gmane.org> 2012-07-28 11:40 ` Shawn Guo 2012-07-28 11:40 ` Shawn Guo [not found] ` <20120728113957.GE2128-rvtDTF3kK1ictlrPMvKcciBecyulp+rMXqFh9Ls21Oc@public.gmane.org> 2012-07-28 11:42 ` Marek Vasut 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 2012-07-23 20:40 ` Marek Vasut 2012-07-24 9:25 ` [PATCH 00/10 V2] MXS SPI driver Attila Kinali 2012-07-24 9:25 ` 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 14:30 ` Maxime Ripard [not found] ` <1344004239-22868-1-git-send-email-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> 2012-08-03 14:43 ` Shawn Guo 2012-08-03 14:43 ` Shawn Guo [not found] ` <20120803144326.GE23791-rvtDTF3kK1ictlrPMvKcciBecyulp+rMXqFh9Ls21Oc@public.gmane.org> 2012-08-03 16:27 ` Maxime Ripard 2012-08-03 16:27 ` Maxime Ripard
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