From: David Brownell <david-b@pacbell.net>
To: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
linux-kernel@vger.kernel.org,
Shannon Nelson <shannon.nelson@intel.com>,
kernel@avr32linux.org, "Francis Moreau" <francis.moro@gmail.com>,
"Paul Mundt" <lethal@linux-sh.org>,
"Vladimir A. Barinov" <vbarinov@ru.mvista.com>,
Pierre Ossman <drzeus-list@drzeus.cx>
Subject: Re: [RFC v2 0/5] dmaengine: Slave DMA interface and example users
Date: Tue, 29 Jan 2008 22:56:14 -0800 [thread overview]
Message-ID: <200801292256.14553.david-b@pacbell.net> (raw)
In-Reply-To: <20080129215453.1e3758ab@siona>
On Tuesday 29 January 2008, Haavard Skinnemoen wrote:
>
> Btw, there's one issue I forgot to mention: I believe the DMA Engine
> framework is currently misusing the DMA mapping API, and this patchset
> makes things worse.
>
> Currently, the async_tx bits of the API do the required calls to
> dma_map_single() and/or dma_map_page(), but they rely on the driver to
> do the unmapping. This is problematic ...
>
> How do we solve this?
How about: for peripheral DMA, don't let the engine see anything
except dma_addr_t values.
The engine needs to be able to dma_alloc_coherent() memory too,
which is pre-mapped.
- Dave
next prev parent reply other threads:[~2008-01-30 7:30 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-29 18:10 [RFC v2 0/5] dmaengine: Slave DMA interface and example users Haavard Skinnemoen
2008-01-29 18:10 ` [RFC v2 1/5] dmaengine: Add dma_client parameter to device_alloc_chan_resources Haavard Skinnemoen
2008-01-29 18:10 ` [RFC v2 2/5] dmaengine: Add slave DMA interface Haavard Skinnemoen
2008-01-29 18:10 ` [RFC v2 3/5] dmaengine: Make DMA Engine menu visible for AVR32 users Haavard Skinnemoen
2008-01-29 18:10 ` [RFC v2 4/5] dmaengine: Driver for the Synopsys DesignWare DMA controller Haavard Skinnemoen
2008-01-29 18:10 ` [RFC v2 5/5] Atmel MCI: Driver for Atmel on-chip MMC controllers Haavard Skinnemoen
2008-02-13 18:30 ` Pierre Ossman
2008-02-13 18:47 ` Haavard Skinnemoen
2008-02-14 14:00 ` MMC core debugfs support (was Re: [RFC v2 5/5] Atmel MCI: Driver for Atmel on-chip MMC controllers) Haavard Skinnemoen
2008-02-25 17:12 ` Pierre Ossman
2008-02-13 19:11 ` [RFC v2 5/5] Atmel MCI: Driver for Atmel on-chip MMC controllers Dan Williams
2008-02-13 21:06 ` Haavard Skinnemoen
2008-02-13 23:55 ` Dan Williams
2008-02-14 8:36 ` Haavard Skinnemoen
2008-02-14 18:34 ` Dan Williams
2008-02-14 19:21 ` Haavard Skinnemoen
2008-01-30 18:53 ` [RFC v2 4/5] dmaengine: Driver for the Synopsys DesignWare DMA controller Dan Williams
2008-01-30 7:30 ` [RFC v2 2/5] dmaengine: Add slave DMA interface David Brownell
2008-01-30 9:27 ` Haavard Skinnemoen
2008-01-30 10:52 ` David Brownell
2008-01-30 12:26 ` Haavard Skinnemoen
2008-01-31 8:27 ` David Brownell
2008-01-31 8:44 ` Paul Mundt
2008-01-31 12:51 ` David Brownell
2008-01-31 14:12 ` Haavard Skinnemoen
2008-01-31 13:52 ` Haavard Skinnemoen
2008-02-06 21:08 ` Dan Williams
2008-02-07 17:56 ` Haavard Skinnemoen
2008-01-30 18:28 ` Dan Williams
2008-01-30 20:45 ` David Brownell
2008-01-31 6:35 ` SDIO driver not receiving responses Farbod Nejati
2008-02-07 19:51 ` Pierre Ossman
2008-01-29 20:54 ` [RFC v2 0/5] dmaengine: Slave DMA interface and example users Haavard Skinnemoen
2008-01-30 6:56 ` David Brownell [this message]
2008-01-30 8:56 ` Haavard Skinnemoen
2008-01-30 17:39 ` Dan Williams
2008-02-04 15:32 ` Haavard Skinnemoen
2008-02-06 18:46 ` Dan Williams
2008-02-07 17:52 ` Haavard Skinnemoen
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