Re: [PATCH 07/13] dmaengine: introduce dma_request_channel and private channels

From: Dan Williams
Date: Tue Dec 02 2008 - 12:16:21 EST

On Tue, Dec 2, 2008 at 8:52 AM, Guennadi Liakhovetski
<g.liakhovetski@xxxxxx> wrote:
> Hi Dan,
> I think, there is a problem with your dma_request_channel() /
> private_candidate() implementation: your current version only tries one
> channel from a dma device list, which matched capabilities. If this
> channel is not accepted by the client, you do not try other channels from
> this device and just go to the next one...

Which dma driver are you using? The dmaengine code assumes that all
channels on a device are equal. It sounds like there are differences
between peer-channels on the device in this case. If the driver
registers a device per channel that should give the flexibility you

> Another problem I encountered with my framebuffer is the initialisation
> order. You initialise dmaengine per subsys_initcall(), whereas the only
> way to guarantee the order:
> dmaengine
> dma-device driver
> framebuffer

hmm... can the framebuffer be moved to late_initcall?

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