NHLT fetch based on _DSM prevents ACPI table override mechanism from being utilized. Make use of acpi_get_table to enable it and get rid of redundant code. In consequence, NHLT can be overridden just like any other ACPI table, e.g.: DSDT or SSDT.
Change has been verified on all Intel AVS architecture platforms, RVP and production laptops both.
Change possible due to addition of NHLT signature to the list of standard ACPI tables: https://patchwork.kernel.org/patch/11463235/
Override helps not only with debug purposes but also allows user for table adjustment when one found on their production hardware is invalid. Shared official NHLT spec is now available to community at: https://01.org/blogs/intel-smart-sound-technology-audio-dsp
NHLT support for iASL is still ongoing subject but should be available in nearest future.
Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com ---
Changes in v2: - commit message update, no functional changes
sound/hda/intel-nhlt.c | 49 +++++++----------------------------------- 1 file changed, 8 insertions(+), 41 deletions(-)
diff --git a/sound/hda/intel-nhlt.c b/sound/hda/intel-nhlt.c index 99a23fe7fab9..2f741d2792d8 100644 --- a/sound/hda/intel-nhlt.c +++ b/sound/hda/intel-nhlt.c @@ -4,58 +4,25 @@ #include <linux/acpi.h> #include <sound/intel-nhlt.h>
-#define NHLT_ACPI_HEADER_SIG "NHLT" - -/* Unique identification for getting NHLT blobs */ -static const guid_t osc_guid = - GUID_INIT(0xA69F886E, 0x6CEB, 0x4594, - 0xA4, 0x1F, 0x7B, 0x5D, 0xCE, 0x24, 0xC5, 0x53); - struct nhlt_acpi_table *intel_nhlt_init(struct device *dev) { - acpi_handle handle; - union acpi_object *obj; - struct nhlt_resource_desc *nhlt_ptr; - struct nhlt_acpi_table *nhlt_table = NULL; - - handle = ACPI_HANDLE(dev); - if (!handle) { - dev_err(dev, "Didn't find ACPI_HANDLE\n"); - return NULL; - } + struct nhlt_acpi_table *nhlt; + acpi_status status;
- obj = acpi_evaluate_dsm(handle, &osc_guid, 1, 1, NULL); - - if (!obj) - return NULL; - - if (obj->type != ACPI_TYPE_BUFFER) { - dev_dbg(dev, "No NHLT table found\n"); - ACPI_FREE(obj); + 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; }
- nhlt_ptr = (struct nhlt_resource_desc *)obj->buffer.pointer; - if (nhlt_ptr->length) - nhlt_table = (struct nhlt_acpi_table *) - memremap(nhlt_ptr->min_addr, nhlt_ptr->length, - MEMREMAP_WB); - ACPI_FREE(obj); - if (nhlt_table && - (strncmp(nhlt_table->header.signature, - NHLT_ACPI_HEADER_SIG, - strlen(NHLT_ACPI_HEADER_SIG)) != 0)) { - memunmap(nhlt_table); - dev_err(dev, "NHLT ACPI header signature incorrect\n"); - return NULL; - } - return nhlt_table; + return nhlt; } EXPORT_SYMBOL_GPL(intel_nhlt_init);
void intel_nhlt_free(struct nhlt_acpi_table *nhlt) { - memunmap((void *)nhlt); + acpi_put_table((struct acpi_table_header *)nhlt); } EXPORT_SYMBOL_GPL(intel_nhlt_free);