Re: [PATCH] ALSA: hda: Refactor Intel NHLT init

[Takashi Iwai <tiwai@suse.de>]

On Thu, 23 Apr 2020 13:21:36 +0200,
Cezary Rojewski wrote:
> 
> 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.
> 
> Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>

This looks like a nice cleanup and I'll happily apply if anyone can
test with the actual hardware -- currently mine has no DSP, so unable
to check.


thanks,

Takashi

> ---
>  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);
>  
> -- 
> 2.17.1
>