[PATCH 2/3] tpm-chip: Return TPM error codes from auto_startup functions

[Alexander Steffen <Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>]

The auto_startup functions for TPM1 and TPM2 convert all TPM error codes to
ENODEV on exit. But since there is only one caller for those functions,
this code can be consolidated within the caller. Additionally, this allows
the caller to distinguish between a TPM being present (but returning error
responses for some commands) and no TPM being present (or the TPM
malfunctioning completely).

Signed-off-by: Alexander Steffen <Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>
---
 drivers/char/tpm/tpm-chip.c      | 4 +++-
 drivers/char/tpm/tpm-interface.c | 6 ++----
 drivers/char/tpm/tpm2-cmd.c      | 5 ++---
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index a353b7a..f20fcb7 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -404,8 +404,10 @@ int tpm_chip_register(struct tpm_chip *chip)
 			rc = tpm2_auto_startup(chip);
 		else
 			rc = tpm1_auto_startup(chip);
-		if (rc)
+		if (rc < 0)
 			return rc;
+		else if (rc > 0)
+			return -ENODEV;
 	}
 
 	tpm_sysfs_add_device(chip);
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 3123a6e..4784ccc 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -997,7 +997,8 @@ EXPORT_SYMBOL_GPL(tpm_do_selftest);
  *                     sequence
  * @chip: TPM chip to use
  *
- * Returns 0 on success, < 0 in case of fatal error.
+ * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
+ * a TPM error code.
  */
 int tpm1_auto_startup(struct tpm_chip *chip)
 {
@@ -1012,10 +1013,7 @@ int tpm1_auto_startup(struct tpm_chip *chip)
 		goto out;
 	}
 
-	return rc;
 out:
-	if (rc > 0)
-		rc = -ENODEV;
 	return rc;
 }
 
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index f7f34b2a..0a64714 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -1074,7 +1074,8 @@ static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
  *                     sequence
  * @chip: TPM chip to use
  *
- * Returns 0 on success, < 0 in case of fatal error.
+ * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
+ * a TPM error code.
  */
 int tpm2_auto_startup(struct tpm_chip *chip)
 {
@@ -1109,8 +1110,6 @@ int tpm2_auto_startup(struct tpm_chip *chip)
 	rc = tpm2_get_cc_attrs_tbl(chip);
 
 out:
-	if (rc > 0)
-		rc = -ENODEV;
 	return rc;
 }
 
-- 
2.7.4


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