ACPI REV override for Dell XPS 13 9343

[Cezary Rojewski]

On 2022-06-13 3:05 PM, Pierre-Louis Bossart wrote:
> On 6/13/22 05:53, Cezary Rojewski wrote:
>> Hello,
>>
>> It's been a while since catpt-driver [1] has been introduced to provide
>> full support for Broadwell (BDW) machines with Intel DSP. For BDW, audio
>> devices can make use of DSP only in I2S mode. In 2015 Rafael and Dominik
>> provided quirk [2] for Dell XPS 13 9343. Given the description:
>>
>> _For example, based on what ACPI exports as the supported revision, Dell
>> XPS 13 (2015) configures its audio device to either work in HDA mode or
>> in I2S mode, where the former is supposed to be used on Linux until the
>> latter is fully supported (in the kernel as well as in user space)._
>>
>> It's clear that such configuration was not fully supported back then. I
>> believe now it is. Perhaps it is time to let the quirk in mention go? By
>> that I mean just the relevant entry, not the ACPI_REV_OVERRIDE_POSSIBLE
>> functionality as a whole.
> 
> This should be a distribution or power-user decision to enable the I2S
> version IMHO.
> 
> There is nothing new in terms of functionality with the I2S version, so
> limited added-value that doesn't offset the added risk due to the
> dependencies on mixer settings that may or may not be installed (UCM, etc).
> 
> If it ain't broke don't fix it.


Not much of a fan of the last statement. I believe challenging status 
quo is the right thing to do. We do not want to bloat the kernel with 
unnecessary quirks.

The broadwell-rt286 UCM is part of alsa-ucm-conf repo for years now.


Regards,
Czarek