[PATCH v2 3/4] tpm: tpm_tis: Use cached tpm2_acpi_start_method

[Siddharth Chintamaneni <sidchintamaneni@gmail.com>]

Use the cached tpm2_acpi_start_method value in check_acpi_tpm2() instead
of mapping and unmapping the ACPI TPM2 table again during probe.

Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
---
 drivers/char/tpm/tpm_tis.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 6f8344894ea5..a6fb6f889e7d 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -138,28 +138,24 @@ MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
 static int check_acpi_tpm2(struct device *dev)
 {
 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
-	struct acpi_table_tpm2 *tbl;
-	acpi_status st;
-	int ret = 0;
 
 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
 		return 0;
 
-	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
-	 * table is mandatory
+	/*
+	 * If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
+	 * table is mandatory.
 	 */
-	st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
-	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
+	if (tpm2_acpi_start_method == ACPI_TPM2_NOT_ALLOWED) {
 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
 		return -EINVAL;
 	}
 
 	/* The tpm2_crb driver handles this device */
-	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
-		ret = -ENODEV;
+	if (tpm2_acpi_start_method != ACPI_TPM2_MEMORY_MAPPED)
+		return -ENODEV;
 
-	acpi_put_table((struct acpi_table_header *)tbl);
-	return ret;
+	return 0;
 }
 #else
 static int check_acpi_tpm2(struct device *dev)
-- 
2.45.4