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From: Mark Brown <broonie@kernel.org>
To: Michal Suchanek <hramrach@gmail.com>
Cc: "Heiner Kallweit" <hkallweit1@gmail.com>,
	"David Woodhouse" <dwmw2@infradead.org>,
	"Brian Norris" <computersforpeace@gmail.com>,
	"Han Xu" <han.xu@freescale.com>,
	"Boris Brezillon" <boris.brezillon@free-electrons.com>,
	"Javier Martinez Canillas" <javier@osg.samsung.com>,
	"Stephen Warren" <swarren@nvidia.com>,
	"Andrew F. Davis" <afd@ti.com>, "Marek Vasut" <marex@denx.de>,
	"Rafał Miłecki" <zajec5@gmail.com>,
	"Mika Westerberg" <mika.westerberg@linux.intel.com>,
	"Gabor Juhos" <juhosg@openwrt.org>,
	"Bean Huo 霍斌斌" <beanhuo@micron.com>,
	"Furquan Shaikh" <furquan@google.com>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-spi@vger.kernel.org
Subject: Re: [PATCH v5 08/10] spi: expose master transfer size limitation.
Date: Tue, 1 Dec 2015 19:58:16 +0000	[thread overview]
Message-ID: <20151201195816.GS1929@sirena.org.uk> (raw)
In-Reply-To: <8c34c7790244489c2ce0072c72bd9bc7c4cdb965.1448988089.git.hramrach@gmail.com>

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On Tue, Dec 01, 2015 at 04:51:06PM -0000, Michal Suchanek wrote:
> On some SPI controllers it is not feasible to transfer arbitrary amount
> of data at once.
> 
> When the limit on transfer size is a few kilobytes at least it makes
> sense to use the SPI hardware rather than reverting to gpio driver.

> +	/*
> +	 * on some hardware transfer size may be constrained
> +	 * the limit may depend on device transfer settings
> +	 */
> +	size_t (*max_transfer_size)(struct spi_device *spi);

Heiner submitted a *very* similar patch just now with a straight
variable plus accessor instead of a function and using a name with _msg.
I'm ambivalent on the implementation but prefer the naming here since
that's more the limitation we're trying to express I think (some
hardware does have limiations about multple transfers too).  Can the two
of you come up with something that works for both of you?

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WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Michal Suchanek <hramrach-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: "Heiner Kallweit"
	<hkallweit1-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	"David Woodhouse" <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
	"Brian Norris"
	<computersforpeace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	"Han Xu" <han.xu-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
	"Boris Brezillon"
	<boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
	"Javier Martinez Canillas"
	<javier-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>,
	"Stephen Warren"
	<swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
	"Andrew F. Davis" <afd-l0cyMroinI0@public.gmane.org>,
	"Marek Vasut" <marex-ynQEQJNshbs@public.gmane.org>,
	"Rafał Miłecki" <zajec5-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	"Mika Westerberg"
	<mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
	"Gabor Juhos" <juhosg-p3rKhJxN3npAfugRpC6u6w@public.gmane.org>,
	"Bean Huo 霍斌斌" <beanhuo-AL4WhLSQfzjQT0dZR+AlfA@public.gmane.org>,
	"Furquan Shaikh"
	<furquan-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH v5 08/10] spi: expose master transfer size limitation.
Date: Tue, 1 Dec 2015 19:58:16 +0000	[thread overview]
Message-ID: <20151201195816.GS1929@sirena.org.uk> (raw)
In-Reply-To: <8c34c7790244489c2ce0072c72bd9bc7c4cdb965.1448988089.git.hramrach-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

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On Tue, Dec 01, 2015 at 04:51:06PM -0000, Michal Suchanek wrote:
> On some SPI controllers it is not feasible to transfer arbitrary amount
> of data at once.
> 
> When the limit on transfer size is a few kilobytes at least it makes
> sense to use the SPI hardware rather than reverting to gpio driver.

> +	/*
> +	 * on some hardware transfer size may be constrained
> +	 * the limit may depend on device transfer settings
> +	 */
> +	size_t (*max_transfer_size)(struct spi_device *spi);

Heiner submitted a *very* similar patch just now with a straight
variable plus accessor instead of a function and using a name with _msg.
I'm ambivalent on the implementation but prefer the naming here since
that's more the limitation we're trying to express I think (some
hardware does have limiations about multple transfers too).  Can the two
of you come up with something that works for both of you?

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  reply	other threads:[~2015-12-01 19:58 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-01 16:51 [PATCH v5 00/10] add error checking to spi-nor read and write Michal Suchanek
2015-12-01 16:51 ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 01/10] mtd: spi-nor: change return value of read/write Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 02/10] mtd: m25p80: return amount of data transferred or error in read/write Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 04/10] mtd: spi-nor: check return value from read/write Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 03/10] mtd: fsl-quadspi: return amount of data read/written or error Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 07/10] mtd: spi-nor: add read loop Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 06/10] mtd: spi-nor: simplify write loop Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 05/10] mtd: spi-nor: stop passing around retlen Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 08/10] spi: expose master transfer size limitation Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 19:58   ` Mark Brown [this message]
2015-12-01 19:58     ` Mark Brown
2015-12-01 21:07     ` Heiner Kallweit
2015-12-01 21:07       ` Heiner Kallweit
2015-12-01 21:31       ` Mark Brown
2015-12-01 21:31         ` Mark Brown
2015-12-02  9:55     ` Michal Suchanek
2015-12-02  9:55       ` Michal Suchanek
2015-12-01 23:12   ` Mark Brown
2015-12-02  9:38     ` Michal Suchanek
2015-12-02  9:38       ` Michal Suchanek
2015-12-04 14:30     ` Martin Sperl
2015-12-04 14:30       ` Martin Sperl
2015-12-04 16:45       ` Michal Suchanek
2015-12-04 16:45         ` Michal Suchanek
2015-12-07 20:18       ` Mark Brown
2015-12-07 20:18         ` Mark Brown
2015-12-01 16:51 ` [PATCH v5 10/10] spi: m25p80: read in spi_max_transfer_size chunks Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek
2015-12-01 16:51 ` [PATCH v5 09/10] spi: fsl-espi: expose maximum transfer size limit Michal Suchanek
2015-12-01 16:51   ` Michal Suchanek

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