[alsa-devel] [PATCH v1] ASoC: bcm2835: Remove redundant channel checking code in hw_params

[Matt Flax]

On 01/02/17 21:53, Mark Brown wrote:
> On Wed, Feb 01, 2017 at 03:45:03PM +1100, Matt Flax wrote:
>
>> This redundant channel count check may seem like it will not cause
>> any problems however some sound cards (such as the 8 channel
>> AudioInjector Octo sound card) require the execution of the
>> bcm2835_i2s_hw_params function when channels_max in the
>> bcm2835_i2s_dai structure has been increased to 8.
>> As the channel checking code in bcm2835_i2s_hw_params is redundant
>> and stops certain cards from working it has been removed.
> If those cards add support for higher channel counts they should be
> adding real support for that in the driver, not just hacking out
> defensive code.  If the device can usefully do 8 channels then modify
> the driver to do 8 channels.  Otherwise people are going to need to
> modify the driver anyway to remove the limits in the constraints.
>
Indeed the AudioInjector Octo sound card is currently operating @ 8 
channels out on the bcm2835 silicon. It has been tested on both the Pi 2 
and Pi 3.

Do you mean that I should increase bcm2835_i2s_dai.channels_max to 8 ?

I can do this. Does anyone have any objections to this approach ?

thanks

Matt

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