Re: [PATCH 2/2] ASoC: xilinx: xlnx_i2s: Discover parameters from registers

[Sean Anderson <sean.anderson@linux.dev>]

On 1/29/26 12:27, Mark Brown wrote:
> On Thu, Jan 29, 2026 at 12:23:15PM -0500, Sean Anderson wrote:
> 
>> -	ret = of_property_read_u32(node, "xlnx,num-channels", &drv_data->channels);
> 
>> -	ret = of_property_read_u32(node, "xlnx,dwidth", &drv_data->data_width);
> 
> Given that the properties already exist it seems wise to continue to
> parse them if available and prefer them over what we read from the
> hardware, it would not shock me to discover that hardware exists where
> the registers are inaccurate or need overriding due to bugs.

I would be surprised if such hardware exists. These properties are
automatically generated by Xilinx's tools based on the HDL core's
properties. This has a few consequences:

- They always exactly match the hardware unless someone has gone in and
  modified them. I think this is unlikely in this case because they
  directly reflect parameters that should not need to be adjusted.
- Driver authors tend to use them even when there are hardware registers
  available with the same information, as Xilinx has not always been
  consistent in adding such registers.

I am not aware of any errata regarding incorrect generation of
properties for this device or cases where the number of channels or bit
depth was incorrect.

--Sean