Commit 8c575883 authored by Pierre-Louis Bossart's avatar Pierre-Louis Bossart Committed by Takashi Iwai
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ALSA: hda/intel: stop probe if DMICS are detected on Skylake+ platforms 



The legacy HD-Audio driver cannot handle Skylake+ platforms with
digital microphones. For those platforms, the SOF or SST drivers need
to be used.

This patch provides an automatic way of detecting the presence of
DMICs using NHTL information reported by the BIOS. A kernel kconfig
option or a kernel module parameter provide an opt-in means of
stopping the probe. The kernel would then look for an alternate driver
registered for the same PCI ID to probe.

With this capability, distros no longer have to blacklist
snd-hda-intel, but still need to make sure the SOF/SST drivers are
functional by providing the relevant firmware and topology files in
/lib/firmware/intel

The coexistence between SOF and SST drivers and their dynamic
detection is not addressed by this patch, different mechanisms need to
be used, e.g. DMI-based quirks.

Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 1169cbf6

sound/pci/hda/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ config SND_HDA_INTEL 
	tristate "HD Audio PCI"

	depends on SND_PCI

	select SND_HDA

	select SND_INTEL_NHLT if ACPI

	help

	  Say Y here to include support for Intel "High Definition

	  Audio" (Azalia) and its compatible devices.
@@ -22,6 +23,15 @@ config SND_HDA_INTEL 
	  To compile this driver as a module, choose M here: the module

	  will be called snd-hda-intel.



config SND_HDA_INTEL_DETECT_DMIC

	bool "DMIC detection and probe abort"

	depends on SND_HDA_INTEL

	help

	  Say Y to detect digital microphones on SKL+ devices. DMICs

	  cannot be handled by the HDaudio legacy driver and are

	  currently only supported by the SOF driver.

	  If unsure say N.



config SND_HDA_TEGRA

	tristate "NVIDIA Tegra HD Audio"

	depends on ARCH_TEGRA

sound/pci/hda/hda_intel.c

+34 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
#include <sound/initval.h>

#include <sound/hdaudio.h>

#include <sound/hda_i915.h>

#include <sound/intel-nhlt.h>

#include <linux/vgaarb.h>

#include <linux/vga_switcheroo.h>

#include <linux/firmware.h>
@@ -124,6 +125,7 @@ static char *patch[SNDRV_CARDS]; 
static bool beep_mode[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] =

					CONFIG_SND_HDA_INPUT_BEEP_MODE};

#endif

static bool dmic_detect = IS_ENABLED(CONFIG_SND_HDA_INTEL_DETECT_DMIC);



module_param_array(index, int, NULL, 0444);

MODULE_PARM_DESC(index, "Index value for Intel HD audio interface.");
@@ -158,6 +160,8 @@ module_param_array(beep_mode, bool, NULL, 0444); 
MODULE_PARM_DESC(beep_mode, "Select HDA Beep registration mode "

			    "(0=off, 1=on) (default=1).");

#endif

module_param(dmic_detect, bool, 0444);

MODULE_PARM_DESC(dmic_detect, "DMIC detect on SKL+ platforms");



#ifdef CONFIG_PM

static int param_set_xint(const char *val, const struct kernel_param *kp);
@@ -2025,6 +2029,25 @@ static const struct hda_controller_ops pci_hda_ops = { 
	.position_check = azx_position_check,

};



static int azx_check_dmic(struct pci_dev *pci, struct azx *chip)

{

	struct nhlt_acpi_table *nhlt;

	int ret = 0;



	if (chip->driver_type == AZX_DRIVER_SKL &&

	    pci->class != 0x040300) {

		nhlt = intel_nhlt_init(&pci->dev);

		if (nhlt) {

			if (intel_nhlt_get_dmic_geo(&pci->dev, nhlt)) {

				ret = -ENODEV;

				dev_info(&pci->dev, "Digital mics found on Skylake+ platform, aborting probe\n");

			}

			intel_nhlt_free(nhlt);

		}

	}

	return ret;

}



static int azx_probe(struct pci_dev *pci,

		     const struct pci_device_id *pci_id)

{
@@ -2055,6 +2078,17 @@ static int azx_probe(struct pci_dev *pci, 
	card->private_data = chip;

	hda = container_of(chip, struct hda_intel, chip);



	/*

	 * stop probe if digital microphones detected on Skylake+ platform

	 * with the DSP enabled. This is an opt-in behavior defined at build

	 * time or at run-time with a module parameter

	 */

	if (dmic_detect) {

		err = azx_check_dmic(pci, chip);

		if (err < 0)

			goto out_free;

	}



	pci_set_drvdata(pci, card);



	err = register_vga_switcheroo(chip);

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