From: Jarkko Nikula <jhnikula@gmail.com>
To: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
"tony@atomide.com" <tony@atomide.com>,
"broonie@opensource.wolfsonmicro.com"
<broonie@opensource.wolfsonmicro.com>,
"Valentin Eduardo (Nokia-D/Helsinki)"
<eduardo.valentin@nokia.com>,
"Nurkkala Eero.An (EXT-Offcode/Oulu)"
<ext-Eero.Nurkkala@nokia.com>, Girdwood <lrg@slimlogic.co.uk>
Subject: Re: [alsa-devel] [RFC PATCH 5/5] ASoC: omap-mcbsp: Place correct constraints for streams
Date: Tue, 1 Jun 2010 14:20:47 +0300 [thread overview]
Message-ID: <20100601142047.c6a549a8.jhnikula@gmail.com> (raw)
In-Reply-To: <201006011330.11044.peter.ujfalusi@nokia.com>
On Tue, 1 Jun 2010 13:30:10 +0300
Peter Ujfalusi <peter.ujfalusi@nokia.com> wrote:
> Because, if you want to transfer in one SDMA burst more than the space free in
> the McBSP FIFO, than where would the rest go?
>
I would have expected peripheral to deassert the DMA request but I
haven't read the TRM so detail and experimenting with bigger period
sizes didn't work so some /dev/null effect was obviously happening :-)
> I guess it could be better than having 128 word long periods on McBSP1, 3, 4,
> and 5. With small period size the applications also need to be woken up, but if
> we silently handling the DMA IRQs, and the application is only woken up by every
> 10. DMA IRQ, it might still save some power?
>
This is worth to experiment. Probably more interrupts with or without
application wakeup reduction does not increase power as much as the
savings are from core clocks being more idle.
--
Jarkko
next prev parent reply other threads:[~2010-06-01 11:20 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-31 8:16 [RFC PATCH 0/5] OMAP/ASoC: McBSP: FIFO handling related fixes Peter Ujfalusi
2010-05-31 8:16 ` [RFC PATCH 1/5] OMAP: McBSP: Function to query the FIFO size Peter Ujfalusi
2010-05-31 8:16 ` [RFC PATCH 2/5] OMAP3: McBSP: Change the way how the FIFO is handled Peter Ujfalusi
2010-05-31 17:41 ` Nishanth Menon
2010-06-01 6:59 ` Peter Ujfalusi
2010-06-02 4:24 ` Nishanth Menon
2010-05-31 8:16 ` [RFC PATCH 3/5] OMAP3: McBSP: Use the port's buffer_size when calculating tx delay Peter Ujfalusi
2010-05-31 8:16 ` [RFC PATCH 4/5] ASoC: omap-mcbsp: Save, and use wlen for threshold configuration Peter Ujfalusi
2010-05-31 8:16 ` [RFC PATCH 5/5] ASoC: omap-mcbsp: Place correct constraints for streams Peter Ujfalusi
2010-05-31 8:41 ` Peter Ujfalusi
2010-05-31 10:00 ` [alsa-devel] " Liam Girdwood
2010-05-31 11:57 ` Peter Ujfalusi
2010-06-01 6:38 ` Jarkko Nikula
2010-06-01 6:47 ` Peter Ujfalusi
2010-06-01 7:38 ` Jarkko Nikula
2010-06-01 8:07 ` Peter Ujfalusi
2010-06-01 8:19 ` Peter Ujfalusi
2010-06-01 9:29 ` Jarkko Nikula
2010-06-01 10:30 ` Peter Ujfalusi
2010-06-01 11:20 ` Jarkko Nikula [this message]
2010-06-01 11:34 ` [alsa-devel] " Peter Ujfalusi
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