From: Mark Brown <broonie@kernel.org>
To: Lars-Peter Clausen <lars@metafoo.de>
Cc: Linux-ALSA <alsa-devel@alsa-project.org>,
Simon <horms@verge.net.au>,
Kuninori Morimoto <kuninori.morimoto.gx@gmail.com>,
Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
Liam Girdwood <lgirdwood@gmail.com>
Subject: Re: About snd_dmaengine_pcm_trigger()
Date: Tue, 11 Mar 2014 09:55:55 +0000 [thread overview]
Message-ID: <20140311095555.GI28112@sirena.org.uk> (raw)
In-Reply-To: <531EDBB4.1080008@metafoo.de>
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On Tue, Mar 11, 2014 at 10:47:32AM +0100, Lars-Peter Clausen wrote:
> The reason why we factored out the dmaengine DMA stuff is because
> there is a standard API that hides the implementation details and is
> supposed to behave the same for each system. For PIO you do not have
> such a abstraction layer that hides the details, so I'm not sure how
> similar PIO between different platforms will actually be.
I keep thinking that there ought to be *some* commonality between the
platforms that use FIQs if only in the timer stuff at least. Part of
the reason that doesn't get factored out is that it's normally just a
temporary bodge until DMA is working of course, though Qualcomm do it
because their DMA for the DSP doesn't fit well with dmaengine and the
i.MX AC'97 needs it since the hardware doesn't fully understand AC'97.
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next prev parent reply other threads:[~2014-03-11 9:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 5:20 About snd_dmaengine_pcm_trigger() Kuninori Morimoto
2014-03-05 7:42 ` Lars-Peter Clausen
2014-03-05 8:32 ` Kuninori Morimoto
2014-03-05 9:20 ` Lars-Peter Clausen
2014-03-06 0:22 ` Kuninori Morimoto
2014-03-06 4:36 ` Mark Brown
2014-03-06 4:39 ` Kuninori Morimoto
2014-03-11 4:47 ` Kuninori Morimoto
2014-03-11 9:47 ` Lars-Peter Clausen
2014-03-11 9:55 ` Mark Brown [this message]
2014-03-12 0:28 ` Kuninori Morimoto
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