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From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM:SAMSUNG: Move S3C DMA driver to drivers/dma
Date: Wed, 8 Jun 2011 08:44:11 +0100	[thread overview]
Message-ID: <20110608074411.GA5176@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <BANLkTimy+on-kKAAiWbwoRCVb0A-JgTXBw@mail.gmail.com>

On Wed, Jun 08, 2011 at 09:35:34AM +0530, Jassi Brar wrote:
> In real life, I saw that with the Samsung's SPDIF controller which has
> fifo depth only for a few samples and it gets very demanding if pro
> quality is expected. Aggravate that with high irq-latency under system
> load.
> And in such cases, it is much more preferable to employ system timers
> to generate period_elapsed updates and queue the whole ring buffer as
> one transfer item to be iterated endlessly by dma. Ex, PL330 doesn't
> lend to LLI but can be programmed endlessly looping one transfer item.

So you're talking about the _hardware_ circular buffer case which I
mentioned in my email.  No problem with the DMA engine API as has
already been said - it supports preparation of circular buffers.

So, from everything discussed so far, there's nothing lacking from
the DMA engine API for your purposes.

  reply	other threads:[~2011-06-08  7:44 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-07  7:48 [PATCH] ARM:SAMSUNG: Move S3C DMA driver to drivers/dma root
2011-06-07  8:00 ` Kyungmin Park
2011-06-07  8:09   ` Jassi Brar
2011-06-07  8:15     ` Russell King - ARM Linux
2011-06-07  8:35       ` Kyungmin Park
2011-06-07 10:15       ` Jassi Brar
2011-06-07 18:29         ` Russell King - ARM Linux
2011-06-07 18:43           ` Mark Brown
2011-06-07 19:01             ` Jassi Brar
2011-06-07 21:41               ` Mark Brown
2011-06-08  2:51                 ` Jassi Brar
2011-06-08  8:55                   ` Mark Brown
2011-06-07 22:28               ` Russell King - ARM Linux
2011-06-08  4:05                 ` Jassi Brar
2011-06-08  7:44                   ` Russell King - ARM Linux [this message]
2011-06-07 19:46           ` Jassi Brar
2011-06-07 22:36             ` Russell King - ARM Linux
2011-06-09 18:24               ` Kukjin Kim
2011-06-16 12:56                 ` Kyungmin Park
2011-06-23  6:47                   ` Kukjin Kim
2011-06-07 10:15     ` Linus Walleij
2011-06-07 10:05       ` Koul, Vinod
2011-06-07  8:01 ` Jassi Brar
2011-06-07 15:42 ` Tushar Behera

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