linux/sound/hda/intel-nhlt.c
Mark Pearson a14a621999 ALSA: hda: ignore invalid NHLT table
On some Lenovo systems if the microphone is disabled in the BIOS
only the NHLT table header is created, with no data. This means
the endpoints field is not correctly set to zero - leading to an
unintialised variable and hence invalid descriptors are parsed
leading to page faults.

The Lenovo firmware team is addressing this, but adding a check
preventing invalid tables being parsed is worthwhile.

Tested on a Lenovo T14.

Tested-by: Philipp Leskovitz <philipp.leskovitz@secunet.com>
Reported-by: Philipp Leskovitz <philipp.leskovitz@secunet.com>
Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210302141003.7342-1-markpearson@lenovo.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-04 09:14:36 +01:00

113 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2015-2019 Intel Corporation
#include <linux/acpi.h>
#include <sound/intel-nhlt.h>
struct nhlt_acpi_table *intel_nhlt_init(struct device *dev)
{
struct nhlt_acpi_table *nhlt;
acpi_status status;
status = acpi_get_table(ACPI_SIG_NHLT, 0,
(struct acpi_table_header **)&nhlt);
if (ACPI_FAILURE(status)) {
dev_warn(dev, "NHLT table not found\n");
return NULL;
}
return nhlt;
}
EXPORT_SYMBOL_GPL(intel_nhlt_init);
void intel_nhlt_free(struct nhlt_acpi_table *nhlt)
{
acpi_put_table((struct acpi_table_header *)nhlt);
}
EXPORT_SYMBOL_GPL(intel_nhlt_free);
int intel_nhlt_get_dmic_geo(struct device *dev, struct nhlt_acpi_table *nhlt)
{
struct nhlt_endpoint *epnt;
struct nhlt_dmic_array_config *cfg;
struct nhlt_vendor_dmic_array_config *cfg_vendor;
struct nhlt_fmt *fmt_configs;
unsigned int dmic_geo = 0;
u16 max_ch = 0;
u8 i, j;
if (!nhlt)
return 0;
if (nhlt->header.length <= sizeof(struct acpi_table_header)) {
dev_warn(dev, "Invalid DMIC description table\n");
return 0;
}
for (j = 0, epnt = nhlt->desc; j < nhlt->endpoint_count; j++,
epnt = (struct nhlt_endpoint *)((u8 *)epnt + epnt->length)) {
if (epnt->linktype != NHLT_LINK_DMIC)
continue;
cfg = (struct nhlt_dmic_array_config *)(epnt->config.caps);
fmt_configs = (struct nhlt_fmt *)(epnt->config.caps + epnt->config.size);
/* find max number of channels based on format_configuration */
if (fmt_configs->fmt_count) {
dev_dbg(dev, "%s: found %d format definitions\n",
__func__, fmt_configs->fmt_count);
for (i = 0; i < fmt_configs->fmt_count; i++) {
struct wav_fmt_ext *fmt_ext;
fmt_ext = &fmt_configs->fmt_config[i].fmt_ext;
if (fmt_ext->fmt.channels > max_ch)
max_ch = fmt_ext->fmt.channels;
}
dev_dbg(dev, "%s: max channels found %d\n", __func__, max_ch);
} else {
dev_dbg(dev, "%s: No format information found\n", __func__);
}
if (cfg->device_config.config_type != NHLT_CONFIG_TYPE_MIC_ARRAY) {
dmic_geo = max_ch;
} else {
switch (cfg->array_type) {
case NHLT_MIC_ARRAY_2CH_SMALL:
case NHLT_MIC_ARRAY_2CH_BIG:
dmic_geo = MIC_ARRAY_2CH;
break;
case NHLT_MIC_ARRAY_4CH_1ST_GEOM:
case NHLT_MIC_ARRAY_4CH_L_SHAPED:
case NHLT_MIC_ARRAY_4CH_2ND_GEOM:
dmic_geo = MIC_ARRAY_4CH;
break;
case NHLT_MIC_ARRAY_VENDOR_DEFINED:
cfg_vendor = (struct nhlt_vendor_dmic_array_config *)cfg;
dmic_geo = cfg_vendor->nb_mics;
break;
default:
dev_warn(dev, "%s: undefined DMIC array_type 0x%0x\n",
__func__, cfg->array_type);
}
if (dmic_geo > 0) {
dev_dbg(dev, "%s: Array with %d dmics\n", __func__, dmic_geo);
}
if (max_ch > dmic_geo) {
dev_dbg(dev, "%s: max channels %d exceed dmic number %d\n",
__func__, max_ch, dmic_geo);
}
}
}
dev_dbg(dev, "%s: dmic number %d max_ch %d\n",
__func__, dmic_geo, max_ch);
return dmic_geo;
}
EXPORT_SYMBOL_GPL(intel_nhlt_get_dmic_geo);