Re: [PATCH] ALSA: HDA: intel-sdw-acpi: add kernel parameter to select alternate controller

[Takashi Iwai <tiwai@xxxxxxx>]

On Thu, 08 Feb 2024 17:37:50 +0100,
Pierre-Louis Bossart wrote:
> 
> Existing DSDT or SSDT platforms hard-code clock and frame shape
> configurations. For validation, we'd like to use alternate
> configurations. It's not always possible to generate new tables due to
> missing symbols, and modifying existing objects usually leads to
> AE_OBJECT_EXIST errors.
> 
> The mechanism suggested in this patch is to add a NEW ACPI controller
> device with a different _ADR value. e.g.
> 
>  Scope (_SB_.PC00.RP08.PXSX.HDAS) {
> 
>   	Device (SDWP)
>             {
>                 Name (_ADR, 0x40000001)  // _ADR: Address
> 
> The desired _ADR can be passed as a parameter with
> 
> options snd-intel-sdw-acpi sdw_ctrl_addr=0x40000001
> 
> This solution leads to minimal tables with just what the developers or
> validation engineers need, and without overriding any of the existing
> firmware definitions. It's consistent with the recommendation to
> extend ACPI definitions and not redefine them with a risk of conflict.
> 
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
> Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>

Thanks, applied now.


Takashi