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From: ben-linux@fluff•org (Ben Dooks)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/2] s3c24xx: DMA: don't use autoreload feature
Date: Wed, 08 Sep 2010 00:37:00 +0100	[thread overview]
Message-ID: <4C86CC9C.9070506@fluff.org> (raw)
In-Reply-To: <1283901799-20461-1-git-send-email-anarsoul@gmail.com>

On 08/09/10 00:23, Vasily Khoruzhick wrote:
> Some integrated DMA-capable hardware doesn't like autoreload
> feature of s3c24xx DMA-engine, that's why s3cmci driver
> didn't work with DMA transfers enabled.
> 
> I rewrote DMA driver not to use autoreload feature and removed
> all pre-loading features. Buffer re-load is fast enought to perform
> it in IRQ handler, and anyway I don't see any reason to waste CPU
> cycles on waiting for buffer load. Driver is much simplier now,
> it was tested with s3cmci and s3c24xx-i2s drivers on s3c2442 and
> s3c2410 SoCs and works just nice.

I found this really necessary, especially on systems where some
drivers can keep the cpu irq load high, such as pio hard-discs.

Can this be changed to a flag that is set to control the behaviour
on a per driver basis?

  reply	other threads:[~2010-09-07 23:37 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-07 15:09 [PATCH 0/2] s3c24xx: fix s3cmci DMA support Vasily Khoruzhick
2010-09-07 15:16 ` [PATCH 2/2] s3cmci: minor fixups Vasily Khoruzhick
2010-09-07 23:15   ` Ben Dooks
2010-09-07 23:14 ` [PATCH 0/2] s3c24xx: fix s3cmci DMA support Ben Dooks
2010-09-07 23:23 ` [PATCH 1/2] s3c24xx: DMA: don't use autoreload feature Vasily Khoruzhick
2010-09-07 23:37   ` Ben Dooks [this message]
2010-09-08  6:27     ` Vasily Khoruzhick
  -- strict thread matches above, loose matches on Subject: below --
2010-08-18 15:04 [PATCH 0/2] s3c24xx: fix DMA support for MCI Vasily Khoruzhick
2010-08-18 15:04 ` [PATCH 1/2] s3c24xx: DMA: don't use autoreload feature Vasily Khoruzhick
2010-08-27 20:03   ` Vasily Khoruzhick

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