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Date: Tue, 18 Sep 2012 09:28:44 +0100
From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>,
        Mark Brown <broonie@opensource.wolfsonmicro.com>,
        Liam Girdwood <lrg@ti.com>, Tony Lindgren <tony@atomide.com>,
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        Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>,
        Ricardo Neri <ricardo.neri@ti.com>,
        Lars-Peter Clausen <lars@metafoo.de>
Subject: Re: [PATCH v3 02/15] dmaengine: omap: Add support for pause/resume
	in cyclic dma mode
Message-ID: <20120918082843.GD12445@n2100.arm.linux.org.uk>
References: <1347624358-25582-1-git-send-email-peter.ujfalusi@ti.com> <1347624358-25582-3-git-send-email-peter.ujfalusi@ti.com> <1347851637.1943.125.camel@vkoul-udesk3>
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On Mon, Sep 17, 2012 at 08:43:57AM +0530, Vinod Koul wrote:
> On Fri, 2012-09-14 at 15:05 +0300, Peter Ujfalusi wrote:
> > -       /* FIXME: not supported by platform private API */
> > -       return -EINVAL;
> > +       /* Pause/Resume only allowed with cyclic mode */
> > +       if (!c->cyclic)
> > +               return -EINVAL; 
> This is not a dma restriction right?

This is needed because this is not a real "pause" - it is a stop, which
causes the contents of the DMA engine's FIFOs to be discarded - which
means a subsequent resume will loose data.