tpm_tis: use default timeout value if chip reports it as zero

Since commit 1107d065fd ("tpm_tis: Introduce intermediate layer for
TPM access") Atmel 3203 TPM on ThinkPad X61S (TPM firmware version 13.9)
no longer works.  The initialization proceeds fine until we get and
start using chip-reported timeouts - and the chip reports C and D
timeouts of zero.

It turns out that until commit 8e54caf407 ("tpm: Provide a generic
means to override the chip returned timeouts") we had actually let
default timeout values remain in this case, so let's bring back this
behavior to make chips like Atmel 3203 work again.

Use a common code that was introduced by that commit so a warning is
printed in this case and /sys/class/tpm/tpm*/timeouts correctly says the
timeouts aren't chip-original.

Fixes: 1107d065fd ("tpm_tis: Introduce intermediate layer for TPM access")
Cc: stable@vger.kernel.org
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

drivers/char/tpm/tpm-interface.c

@@ -522,8 +522,7 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 int tpm_get_timeouts(struct tpm_chip *chip)
 {
 	cap_t cap;
-	unsigned long new_timeout[4];
-	unsigned long old_timeout[4];
+	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
 	ssize_t rc;
 
 	if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
@@ -564,11 +563,15 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 		return rc;
 	}
 
-	old_timeout[0] = be32_to_cpu(cap.timeout.a);
-	old_timeout[1] = be32_to_cpu(cap.timeout.b);
-	old_timeout[2] = be32_to_cpu(cap.timeout.c);
-	old_timeout[3] = be32_to_cpu(cap.timeout.d);
-	memcpy(new_timeout, old_timeout, sizeof(new_timeout));
+	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
+	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
+	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
+	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
+	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
+	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
+	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
+	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
+	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 
 	/*
 	 * Provide ability for vendor overrides of timeout values in case
@@ -576,16 +579,24 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 	 */
 	if (chip->ops->update_timeouts != NULL)
 		chip->timeout_adjusted =
-			chip->ops->update_timeouts(chip, new_timeout);
+			chip->ops->update_timeouts(chip, timeout_eff);
 
 	if (!chip->timeout_adjusted) {
-		/* Don't overwrite default if value is 0 */
-		if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
-			int i;
+		/* Restore default if chip reported 0 */
+		int i;
 
+		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
+			if (timeout_eff[i])
+				continue;
+
+			timeout_eff[i] = timeout_old[i];
+			chip->timeout_adjusted = true;
+		}
+
+		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 			/* timeouts in msec rather usec */
-			for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
-				new_timeout[i] *= 1000;
+			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
+				timeout_eff[i] *= 1000;
 			chip->timeout_adjusted = true;
 		}
 	}
@@ -594,16 +605,16 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 	if (chip->timeout_adjusted) {
 		dev_info(&chip->dev,
 			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
-			 old_timeout[0], new_timeout[0],
-			 old_timeout[1], new_timeout[1],
-			 old_timeout[2], new_timeout[2],
-			 old_timeout[3], new_timeout[3]);
+			 timeout_chip[0], timeout_eff[0],
+			 timeout_chip[1], timeout_eff[1],
+			 timeout_chip[2], timeout_eff[2],
+			 timeout_chip[3], timeout_eff[3]);
 	}
 
-	chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
-	chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
-	chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
-	chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
+	chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
+	chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
+	chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
+	chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 
 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 			"attempting to determine the durations");

drivers/char/tpm/tpm_tis.c

@@ -159,7 +159,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 		irq = tpm_info->irq;
 
 	if (itpm)
-		phy->priv.flags |= TPM_TIS_ITPM_POSSIBLE;
+		phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
 
 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
 				 acpi_dev_handle);

drivers/char/tpm/tpm_tis_core.c

@@ -264,7 +264,7 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 	int rc, status, burstcnt;
 	size_t count = 0;
-	bool itpm = priv->flags & TPM_TIS_ITPM_POSSIBLE;
+	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
 
 	if (request_locality(chip, 0) < 0)
 		return -EBUSY;
@@ -740,7 +740,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
 		 vendor >> 16, rid);
 
-	if (!(priv->flags & TPM_TIS_ITPM_POSSIBLE)) {
+	if (!(priv->flags & TPM_TIS_ITPM_WORKAROUND)) {
 		probe = probe_itpm(chip);
 		if (probe < 0) {
 			rc = -ENODEV;
@@ -748,7 +748,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		}
 
 		if (!!probe)
-			priv->flags |= TPM_TIS_ITPM_POSSIBLE;
+			priv->flags |= TPM_TIS_ITPM_WORKAROUND;
 	}
 
 	/* Figure out the capabilities */

drivers/char/tpm/tpm_tis_core.h

@@ -80,7 +80,7 @@ enum tis_defaults {
 #define	TPM_RID(l)			(0x0F04 | ((l) << 12))
 
 enum tpm_tis_flags {
-	TPM_TIS_ITPM_POSSIBLE		= BIT(0),
+	TPM_TIS_ITPM_WORKAROUND		= BIT(0),
 };
 
 struct tpm_tis_data {