The existing wait_for_tpm_stat() checks the chip status before
sleeping for 5 msec in a polling loop.  For some functions although
the status isn't ready immediately, the status returns extremely
quickly. Waiting for 5 msec causes an unnecessary delay. An
example is the send() call in the tpms_tis driver.

This patch defines __wait_for_tpm_stat(), allowing the caller
to specify the polling sleep timeout value within the loop.
The existing wait_for_tpm_stat() becomes a wrapper for this
function.

Signed-off-by: Nayna Jain <redacted>
---
  drivers/char/tpm/tpm-interface.c | 15 ++++++++++++---
  drivers/char/tpm/tpm.h           |  3 +++
  drivers/char/tpm/tpm_tis_core.c  | 11 ++++++-----
  3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 1d6729be4cd6..b23d006243b7 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c

@@ -1050,8 +1050,9 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
  	return false;
  }

-int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
-		      wait_queue_head_t *queue, bool check_cancel)
+int __wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
+		      unsigned int poll_sleep, wait_queue_head_t *queue,
+		      bool check_cancel)
  {
  	unsigned long stop;
  	long rc;

@@ -1085,7 +1086,7 @@ int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
  		}
  	} else {
  		do {
-			tpm_msleep(TPM_TIMEOUT);
+			tpm_msleep(poll_sleep);
  			status = chip->ops->status(chip);
  			if ((status & mask) == mask)
  				return 0;

@@ -1093,6 +1094,14 @@ int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
  	}
  	return -ETIME;
  }
+EXPORT_SYMBOL_GPL(__wait_for_tpm_stat);
+
+int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
+		      wait_queue_head_t *queue, bool check_cancel)
+{
+	return __wait_for_tpm_stat(chip, mask, timeout, TPM_TIMEOUT,
+			queue, check_cancel);
+}
  EXPORT_SYMBOL_GPL(wait_for_tpm_stat);

  #define TPM_ORD_SAVESTATE 152

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 2d5466a72e40..eb2f8818eded 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h

@@ -525,6 +525,9 @@ int tpm_do_selftest(struct tpm_chip *chip);
  unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
  int tpm_pm_suspend(struct device *dev);
  int tpm_pm_resume(struct device *dev);
+int __wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
+		unsigned long timeout, unsigned int poll_sleep,
+		wait_queue_head_t *queue, bool check_cancel);
  int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
  		      wait_queue_head_t *queue, bool check_cancel);

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 6b9bf4c4d434..d1eab29cb447 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c

@@ -268,8 +268,8 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
  	status = tpm_tis_status(chip);
  	if ((status & TPM_STS_COMMAND_READY) == 0) {
  		tpm_tis_ready(chip);
-		if (wait_for_tpm_stat
-		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
+		if (__wait_for_tpm_stat
+		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b, 1,
  		     &priv->int_queue, false) < 0) {
  			rc = -ETIME;
  			goto out_err;

@@ -303,7 +303,8 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
  		if (ignore_burst_count)
  			continue;

-		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+		if (__wait_for_tpm_stat(chip, TPM_STS_VALID,
+					chip->timeout_c, 1,
  					&priv->int_queue, false) < 0) {
  			rc = -ETIME;
  			goto out_err;

@@ -320,8 +321,8 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
  	if (rc < 0)
  		goto out_err;

-	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-				&priv->int_queue, false) < 0) {
+	if (__wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+				1, &priv->int_queue, false) < 0) {
  		rc = -ETIME;
  		goto out_err;
  	}