From: Ben Dooks <ben-linux@fluff.org>
To: Vasily Khoruzhick <anarsoul@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org,
Thomas Kleffel <tk@maintech.de>
Subject: Re: [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?
WARNING: multiple messages have this Message-ID (diff)
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?
next prev parent reply other threads:[~2010-09-07 23:38 UTC|newest]
Thread overview: 18+ 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 15:09 ` Vasily Khoruzhick
2010-09-07 15:16 ` [PATCH 2/2] s3cmci: minor fixups Vasily Khoruzhick
2010-09-07 15:16 ` Vasily Khoruzhick
2010-09-07 23:15 ` Ben Dooks
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 23:14 ` Ben Dooks
2010-09-07 23:23 ` [PATCH 1/2] s3c24xx: DMA: don't use autoreload feature Vasily Khoruzhick
2010-09-07 23:23 ` Vasily Khoruzhick
2010-09-07 23:37 ` Ben Dooks [this message]
2010-09-07 23:37 ` Ben Dooks
2010-09-08 6:27 ` Vasily Khoruzhick
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
2010-08-18 15:04 ` Vasily Khoruzhick
2010-08-27 20:03 ` Vasily Khoruzhick
2010-08-27 20:03 ` Vasily Khoruzhick
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