[coreboot-gerrit] New patch to review for coreboot: acpi/tpm: Gracefully handle missing TPM module.

[Tobias Diedrich (ranma+coreboot@tdiedrich.de)]

Tobias Diedrich (ranma+coreboot at tdiedrich.de) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/13713

-gerrit

commit a0772b48f1db38f268b62af94eb9bb53572888ab
Author: Tobias Diedrich <ranma+coreboot at tdiedrich.de>
Date:   Mon Feb 15 13:13:58 2016 +0100

    acpi/tpm: Gracefully handle missing TPM module.
    
    When TPM support is enabled, verify the TPM_DID_VID field is not
    all zeroes or all ones before returning 0xf in the _STA method.
    
    This avoids these kernel errors when no module is installed:
    [    3.426426] tpm_tis 00:01: tpm_transmit: tpm_send: error -5
    [    3.432049] tpm_tis: probe of 00:01 failed with error -5
    
    Change-Id: Ia089d4232e0986b3bc635d346e68d982e8aecd44
    Signed-off-by: Tobias Diedrich <ranma+coreboot at tdiedrich.de>
---
 src/drivers/pc80/tpm/acpi/tpm.asl | 39 ++++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/src/drivers/pc80/tpm/acpi/tpm.asl b/src/drivers/pc80/tpm/acpi/tpm.asl
index 7755e9b..de25114 100644
--- a/src/drivers/pc80/tpm/acpi/tpm.asl
+++ b/src/drivers/pc80/tpm/acpi/tpm.asl
@@ -21,10 +21,33 @@ Device (TPM)
 	Name (_CID, 0x310cd041)
 	Name (_UID, 1)
 
+	OperationRegion (TREG, SystemMemory,
+			 CONFIG_TPM_TIS_BASE_ADDRESS, 0x5000)
+	Field (TREG, ByteAcc, NoLock, Preserve)
+	{
+		/* TPM_INT_ENABLE_0 */
+		Offset (0x0008),
+		, 3,
+		ITPL, 2,  /* Interrupt type and polarity */
+
+		/* TPM_INT_VECTOR_0 */
+		Offset (0x000C),
+		IVEC, 4,  /* SERIRQ vector */
+
+		/* TPM_DID_VID */
+		Offset (0x0f00),
+		DVID, 32,  /* Device and vendor ID */
+	}
+
 	Method (_STA, 0)
 	{
 #if CONFIG_LPC_TPM && !CONFIG_TPM_DEACTIVATE
-		Return (0xf)
+		If (LAnd (LGreater (DVID, 0), LLess (DVID, 0xffffffff))) {
+			Return (0xf)
+		} Else {
+			/* TPM module missing */
+			Return (0x0)
+		}
 #else
 		Return (0x0)
 #endif
@@ -45,20 +68,6 @@ Device (TPM)
 
 	Method (_CRS, 0, Serialized)
 	{
-		OperationRegion (TREG, SystemMemory,
-				 CONFIG_TPM_TIS_BASE_ADDRESS, 0x5000)
-		Field (TREG, ByteAcc, NoLock, Preserve)
-		{
-			/* TPM_INT_ENABLE_0 */
-			Offset (0x0008),
-			, 3,
-			ITPL, 2,  /* Interrupt type and polarity */
-
-			/* TPM_INT_VECTOR_0 */
-			Offset (0x000C),
-			IVEC, 4,  /* SERIRQ vector */
-		}
-
 		CreateField (^IBUF, ^TIRQ._INT, 32, TVEC)
 		CreateBitField (^IBUF, ^TIRQ._HE, TTYP)
 		CreateBitField (^IBUF, ^TIRQ._LL, TPOL)