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Date: Wed, 27 Jul 2011 12:59:09 +0300
From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: "Koul, Vinod" <vinod.koul@intel.com>
Cc: Jaswinder Singh <jaswinder.singh@linaro.org>,
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Subject: Re: [PATCHv2] DMAEngine: Let dmac drivers to set chan_id
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On Wed, Jul 27, 2011 at 02:32:26PM +0530, Koul, Vinod wrote:
> Can you please help me understand why channel number "x" is important
> and strictly needed by some client?

At least in ep93xx we have even channel numbers for TX and odd for RX (or
vice versa, can't rememeber). This is a hardware restriction. So the client
code then filters the channels based on that using ->chan_id.

As the caps are not per channel, that is the only way I was able to make it
work.