---
Test Plan:
- Run fixed kernel with ATMEL TPM chips and see crash
has been fixed.
- Run fixed kernel with non-ATMEL TPM chips, and confirm
the timeout has not been changed.

 drivers/char/tpm/tpm.h          |  9 ++++++++-
 drivers/char/tpm/tpm_tis_core.c | 19 +++++++++++++++++--
 include/linux/tpm.h             |  2 ++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 283f78211c3a..bc6aa7f9e119 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h

@@ -42,7 +42,9 @@ enum tpm_timeout {
 	TPM_TIMEOUT_RANGE_US = 300,	/* usecs */
 	TPM_TIMEOUT_POLL = 1,	/* msecs */
 	TPM_TIMEOUT_USECS_MIN = 100,      /* usecs */
-	TPM_TIMEOUT_USECS_MAX = 500      /* usecs */
+	TPM_TIMEOUT_USECS_MAX = 500,	/* usecs */

+	TPM_TIMEOUT_WAIT_STAT = 500,	/* usecs */
+	TPM_ATML_TIMEOUT_WAIT_STAT = 15000	/* usecs */
 };
 
 /* TPM addresses */

@@ -189,6 +191,11 @@ static inline void tpm_msleep(unsigned int delay_msec)
 		     delay_msec * 1000);
 };
 
+static inline void tpm_usleep(unsigned int delay_usec)
+{
+	usleep_range(delay_usec - TPM_TIMEOUT_RANGE_US, delay_usec);
+};

+
 int tpm_chip_start(struct tpm_chip *chip);
 void tpm_chip_stop(struct tpm_chip *chip);
 struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 55b9d3965ae1..9ddd4edfe1c2 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c

@@ -80,8 +80,12 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
 		}
 	} else {
 		do {
-			usleep_range(TPM_TIMEOUT_USECS_MIN,
-				     TPM_TIMEOUT_USECS_MAX);
+			if (chip->timeout_wait_stat && 
+				chip->timeout_wait_stat >= TPM_TIMEOUT_WAIT_STAT) {
+				tpm_usleep((unsigned int)(chip->timeout_wait_stat));
+			} else {
+				tpm_usleep((unsigned int)(TPM_TIMEOUT_WAIT_STAT));
+			}

 			status = chip->ops->status(chip);
 			if ((status & mask) == mask)
 				return 0;

@@ -934,6 +938,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
+	/* init timeout for wait_for_tpm_stat */
+	chip->timeout_wait_stat = TPM_TIMEOUT_WAIT_STAT;
 	priv->phy_ops = phy_ops;
 	dev_set_drvdata(&chip->dev, priv);
 

@@ -983,6 +989,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 
 	priv->manufacturer_id = vendor;
 
+	switch (priv->manufacturer_id) {
+	case TPM_VID_ATML:
+        /* ATMEL chip needs longer timeout to avoid crash */
+		chip->timeout_wait_stat = TPM_ATML_TIMEOUT_WAIT_STAT;
+		break;
+	default:
+		chip->timeout_wait_stat = TPM_TIMEOUT_WAIT_STAT;
+	}
+
 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
 	if (rc < 0)
 		goto out_err;

diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index aa11fe323c56..35f2a0260d76 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h

@@ -150,6 +150,7 @@ struct tpm_chip {
 	bool timeout_adjusted;
 	unsigned long duration[TPM_NUM_DURATIONS]; /* jiffies */
 	bool duration_adjusted;
+	unsigned long timeout_wait_stat; /* usecs */
 
 	struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
 

@@ -269,6 +270,7 @@ enum tpm2_cc_attrs {
 #define TPM_VID_INTEL    0x8086
 #define TPM_VID_WINBOND  0x1050
 #define TPM_VID_STM      0x104A
+#define TPM_VID_ATML     0x1114
 
 enum tpm_chip_flags {
 	TPM_CHIP_FLAG_TPM2		= BIT(1),

-- 
2.29.0.vfs.0.0