From: Mark Brown <broonie@kernel.org>
To: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: "Michal Suchanek" <hramrach@gmail.com>,
"Priit Laes" <plaes@plaes.org>, "Chen-Yu Tsai" <wens@csie.org>,
linux-spi <linux-spi@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Emilio López" <emilio@elopez.com.ar>
Subject: Re: [PATCH 1/2] spi: sun4i: add DMA support
Date: Fri, 18 Mar 2016 20:33:52 +0000 [thread overview]
Message-ID: <20160318203352.GL2566@sirena.org.uk> (raw)
In-Reply-To: <20160318202310.GS30977@lukather>
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On Fri, Mar 18, 2016 at 09:23:10PM +0100, Maxime Ripard wrote:
> On Thu, Mar 17, 2016 at 12:54:08PM +0100, Michal Suchanek wrote:
> > Very few device drivers would work with 63byte transfers only and the
> > code for manually driving the CS line in case the DMA engine fails to
> > configure will necessarily go untested most of the time since most
> > systems will have DMA configured properly.
> That's not true. A significant portion would work. I don't like to
> make up numbers, but I guess only the EEPROMs and rather big screens
> wouldn't work.
You'll probably also see devices doing things like firmware downloads,
there's a bunch of applications for larger transfers. Like you say it's
definitely not going to be a universal problem though, there's many
devices that just use SPI for fast register access.
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next prev parent reply other threads:[~2016-03-18 20:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-26 5:56 [PATCH RESEND 0/2] spi: sun4i: add DMA support Priit Laes
2016-02-26 5:56 ` [PATCH 1/2] " Priit Laes
2016-02-26 12:25 ` Mark Brown
2016-02-26 12:51 ` Michal Suchanek
2016-03-06 21:42 ` Maxime Ripard
2016-03-10 9:01 ` Michal Suchanek
2016-03-17 7:27 ` Maxime Ripard
2016-03-17 10:58 ` Michal Suchanek
2016-03-17 11:43 ` Mark Brown
2016-03-17 11:54 ` Michal Suchanek
2016-03-17 11:58 ` Mark Brown
2016-03-18 20:23 ` Maxime Ripard
2016-03-18 20:33 ` Mark Brown [this message]
2016-02-26 5:56 ` [PATCH 2/2] ARM: sunxi: spi: add notice about SPI FIFO limit Priit Laes
2016-03-06 18:12 ` Maxime Ripard
2016-02-26 12:15 ` [PATCH RESEND 0/2] spi: sun4i: add DMA support Mark Brown
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