[alsa-devel] [PATCH v4 0/5] ALSA/HDA: abort probe when DMICs are detected

[Takashi Iwai]

On Mon, 29 Jul 2019 17:51:46 +0200,
Pierre-Louis Bossart wrote:
> 
> This is the second take on same problem of detecting when the HDaudio
> legacy driver can be used and when the SST or SOF drivers are
> required.
> 
> The previous attempt based on a the PCI Class information was a
> resounding failure and broke audio on Linus' laptop, so we need
> additional information to avoid enabling a DSP-based driver without a
> good reason to do so.
> 
> This patchset suggests the use of the NHLT information which *in
> theory* exposes DMIC endpoints. The legacy HDaudio driver cannot
> handle DMICs and will not provide any capture capabilities. Since it's
> typically the first one to probe due to the Makefile order, aborting
> the probe will let the PCI subsystem look for the next driver which
> hopefully will support this capability.
> 
> I tested this patch on 5 devices (SKL, KBL, APL, GLK, WHL), three
> without DMICs and two with, and the detection seems to work as
> planned. Additional testing by Canonical and Endless folks did not
> expose any issues.
> 
> Changes since v3 (Feedback from Cezary)
> Code cleanups (spaces and unnecessary inits)
> Flipped test statement to return on errors and reduce indentation
> Removed ACPI leak by adding missing ACPI_FREE()
> 
> Changes since v2 (Feedback from Takahi and Cezary)
> Added comment in Kconfig to alert the user to the dependency on ACPI
> 
> Changes since v1 (Feedback from Takashi):
> Squashed patch3 in patch2
> Changed log to dbg_info
> Fixed module parameter handling
> 
> Changes since RFC:
> Cosmetic code improvements
> Moved intel-nhlt.h to include/sound
> Moved intel-nhlt.c to sound/hda
> Removed SOC prefixes
> Added full-support for vendor-defined geometries
> Added Kconfig and kernel module parameter to opt-in
> 
> Pierre-Louis Bossart (5):
>   ASoC: Intel: Skylake: move NHLT header to common directory
>   ALSA: hda: move parts of NHLT code to new module
>   ALSA: hda: intel-nhlt: handle NHLT VENDOR_DEFINED DMIC geometry
>   ASoC: Intel: Skylake: use common NHLT module
>   ALSA: hda/intel: stop probe if DMICS are detected on Skylake+
>     platforms

Applied all five patches now.  Thanks.

Mark, the patches are found in topic/hda-dmic branch of sound git
tree, which are based on 5.3-rc1.  If ASoC tree needs these changes,
feel free to pull the branch into yours.


Takashi