[alsa-devel] [PATCH 1/2] ASoC: ux500_pcm: Differentiate between pdata and DT initialisation

[Lee Jones]

On Tue, 03 Dec 2013, Lars-Peter Clausen wrote:

> On 12/03/2013 01:15 PM, Lars-Peter Clausen wrote:
> > On 12/03/2013 01:04 PM, Lee Jones wrote:
> >> On Tue, 03 Dec 2013, Lars-Peter Clausen wrote:
> >>
> >>> On 12/03/2013 11:27 AM, Lee Jones wrote:
> >>>> If booting with full DT support (i.e. DMA too, the last piece of the
> >>>> puzzle), then we don't need to use the compatible_request_channel call
> >>>> back or require some of the historical bumph which probably isn't
> >>>> required by a platform data start-up now either. This will also be
> >>>> ripped out in upcoming commits.
> >>>>
> >>>> Cc: alsa-devel at alsa-project.org
> >>>> Acked-by: Linus Walleij <linus.walleij at linaro.org>
> >>>> Signed-off-by: Lee Jones <lee.jones at linaro.org>
> >>>
> >>> Strictly speaking you do not need the second config, but well considering
> >>> that this will all hopefully be removed soon anyway it should be fine.
> >>
> >> That's true it will, but why don't we need the second config? I won't
> >> want the compat function to be called in the DT case.
> > 
> > It will only be called if it was not possible to request the DMA channel
> > from the DT.
> 
> The logic used to request the channel is basically this (in pseudo code).
> 
> chan = NULL.
> 
> if (of_node && !(flags & NO_DT))
> 	chan = dma_request_slave_channel(...)
> 
> if (!chan && (flags & COMPAT))
> 	chan = dma_request_channel(compat_filter_fn, compat_filter_data);

Okay, fair enough.

But as you say, this should be fine for now. I'll tend to the
left-over cruft when I convert the driver to DT only.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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