From: Andi Shyti <andi.shyti@samsung.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: linux-spi@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
Mark Brown <broonie@kernel.org>,
Sylwester Nawrocki <s.nawrocki@samsung.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Inki Dae <inki.dae@samsung.com>,
Javier Martinez Canillas <javier@osg.samsung.com>
Subject: Re: [PATCH] spi: s3c64xx: Don't request/release DMA channels for each SPI transfer
Date: Fri, 30 Dec 2016 10:31:30 +0900 [thread overview]
Message-ID: <20161230013130.dxs45jtc7fyidx5g@gangnam.samsung> (raw)
In-Reply-To: <1483013971-26446-1-git-send-email-m.szyprowski@samsung.com>
Hi Marek,
On Thu, Dec 29, 2016 at 01:19:31PM +0100, Marek Szyprowski wrote:
> Requesting a DMA channel might be a time consuming operation, so there is
> no need to acquire and release DMA channel for each SPI transfer.
> DMA channels can be requested during driver probe and kept all the time,
> also because there are no shared nor dynamically allocated channels on
> Samsung S3C/S5P/Exynos platforms.
>
> While moving dma_requrest_slave_channel calls, lets switch to
> dma_request_slave_channel_reason(), which returns error codes on failure,
> which can be properly propagated to the caller (this for example defers
> SPI probe when DMA controller is not yet available).
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Thanks!
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Tested-by: Andi Shyti <andi.shyti@samsung.com>
Andi
next prev parent reply other threads:[~2016-12-30 1:31 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20161229121937eucas1p11cd0bb98b21699b0f773ecaeb7c29d26@eucas1p1.samsung.com>
2016-12-29 12:19 ` [PATCH] spi: s3c64xx: Don't request/release DMA channels for each SPI transfer Marek Szyprowski
2016-12-30 1:31 ` Andi Shyti [this message]
2016-12-31 18:26 ` Mark Brown
[not found] ` <20161231182615.tuukfj5fa4wwkwvj-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2017-01-09 7:43 ` Marek Szyprowski
[not found] ` <4bff51ce-2856-88dd-2518-ef8fa0c179e2-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2017-01-09 10:00 ` Mark Brown
[not found] ` <1483013971-26446-1-git-send-email-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-12-30 15:39 ` Krzysztof Kozlowski
2017-01-09 20:02 ` Applied "spi: s3c64xx: Don't request/release DMA channels for each SPI transfer" to the spi tree Mark Brown
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