Re: commit b1ef29725865 (ACPI _REV=2) causes sound regression on Dell XPS 13 [Was: Discussion around quirking the _REV behavior for the XPS 13 (2015) until 4.2]

[Mark Brown <broonie@kernel.org>]

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On Mon, May 11, 2015 at 08:26:58PM +0200, Dominik Brodowski wrote:

Also CCing Matthew who came up with the original version of the version
change and Liam who is one of Intel's audio experts.

> According to an off-list discussion, the sound breakage (and not just some
> jack detection issue) seems to be caused due to alsa-lib being too old.

Right, it needs the userspace configuration files installing.

> The matter is further complicated by the issue that the driver
> asks for some firmware blob intel/IntcPP01.bin which (at least) I
> cannot find anywhere.

As previously advised that firmware is optional.

> Under the no-regression rule, this means that either b1ef29725865 needs
> to be reverted or we need to find another solution to this matter, such as
> an override. And I think it is needed for longer than just for 4.1, as it
> will continue to be cause regressions on quite recent userspace.

Does this also affect other behaviour of the system?  I'd be pretty
unhappy if it introduce power regressions for example, I mostly don't use
audio on my laptops but I care a lot about how long it'll run
disconnected.  It *is* quite a new laptop and my experience installing
was very much that it was in bringup (though quite a bit of this was
userspace).

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