Tearing down DMA transfer setup after DMA client has finished
vinod.koul at intel.com
Thu Dec 8 07:40:18 PST 2016
On Thu, Dec 08, 2016 at 11:44:53AM +0000, Måns Rullgård wrote:
> Vinod Koul <vinod.koul at intel.com> writes:
> > On Wed, Dec 07, 2016 at 04:45:58PM +0000, Måns Rullgård wrote:
> >> Vinod Koul <vinod.koul at intel.com> writes:
> >> > On Tue, Dec 06, 2016 at 01:14:20PM +0000, Måns Rullgård wrote:
> >> >>
> >> >> That's not going to work very well. Device drivers typically request
> >> >> dma channels in their probe functions or when the device is opened.
> >> >> This means that reserving one of the few channels there will inevitably
> >> >> make some other device fail to operate.
> >> >
> >> > No that doesnt make sense at all, you should get a channel only when you
> >> > want to use it and not in probe!
> >> Tell that to just about every single driver ever written.
> > Not really, few do yes which is wrong but not _all_ do that.
> Every driver I ever looked at does. Name one you consider "correct."
That only tells me you haven't looked enough and want to rant!
FWIW look at ALSA-dmaengine lib, thereby every audio driver that uses it. I
could find other examples and go on and on, but that's besides the point and
looks like you don't want to listen to people telling you something..
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