ASoC: tas2781: remove unused acpi_subysystem_id

The acpi_subysystem_id is only written and freed, not read, so
unnecessary.

Signed-off-by: Gergo Koteles <soyer@irl.hu>
Link: https://lore.kernel.org/r/454639336be28d2b50343e9c8366a56b0975e31d.1707456753.git.soyer@irl.hu
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/tas2781.h

@@ -103,7 +103,6 @@ struct tasdevice_priv {
 	struct tm tm;
 
 	enum device_catlog_id catlog_id;
-	const char *acpi_subsystem_id;
 	unsigned char cal_binaryname[TASDEVICE_MAX_CHANNELS][64];
 	unsigned char crc8_lkp_tbl[CRC8_TABLE_SIZE];
 	unsigned char coef_binaryname[64];

sound/pci/hda/tas2781_hda_i2c.c

@@ -111,9 +111,7 @@ static int tas2781_get_i2c_res(struct acpi_resource *ares, void *data)
 static int tas2781_read_acpi(struct tasdevice_priv *p, const char *hid)
 {
 	struct acpi_device *adev;
-	struct device *physdev;
 	LIST_HEAD(resources);
-	const char *sub;
 	int ret;
 
 	adev = acpi_dev_get_first_match_dev(hid, NULL, -1);
@@ -129,18 +127,8 @@ static int tas2781_read_acpi(struct tasdevice_priv *p, const char *hid)
 
 	acpi_dev_free_resource_list(&resources);
 	strscpy(p->dev_name, hid, sizeof(p->dev_name));
-	physdev = get_device(acpi_get_first_physical_node(adev));
 	acpi_dev_put(adev);
 
-	/* No side-effect to the playback even if subsystem_id is NULL*/
-	sub = acpi_get_subsystem_id(ACPI_HANDLE(physdev));
-	if (IS_ERR(sub))
-		sub = NULL;
-
-	p->acpi_subsystem_id = sub;
-
-	put_device(physdev);
-
 	return 0;
 
 err:

sound/soc/codecs/tas2781-comlib.c

@@ -407,7 +407,6 @@ void tasdevice_remove(struct tasdevice_priv *tas_priv)
 {
 	if (gpio_is_valid(tas_priv->irq_info.irq_gpio))
 		gpio_free(tas_priv->irq_info.irq_gpio);
-	kfree(tas_priv->acpi_subsystem_id);
 	mutex_destroy(&tas_priv->codec_lock);
 }
 EXPORT_SYMBOL_GPL(tasdevice_remove);