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 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
.../skl-nhlt.h => include/sound/intel-nhlt.h | 51 +++++++-- sound/hda/Kconfig | 5 + sound/hda/Makefile | 3 + sound/hda/intel-nhlt.c | 102 ++++++++++++++++++ sound/pci/hda/Kconfig | 10 ++ sound/pci/hda/hda_intel.c | 34 ++++++ sound/soc/intel/Kconfig | 1 + sound/soc/intel/skylake/skl-nhlt.c | 91 +--------------- sound/soc/intel/skylake/skl-ssp-clk.c | 1 + sound/soc/intel/skylake/skl-topology.c | 1 + sound/soc/intel/skylake/skl.c | 12 ++- sound/soc/intel/skylake/skl.h | 4 - 12 files changed, 207 insertions(+), 108 deletions(-) rename sound/soc/intel/skylake/skl-nhlt.h => include/sound/intel-nhlt.h (65%) create mode 100644 sound/hda/intel-nhlt.c