1 files changed, 33 insertions, 6 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8d7e4da6ed53..b71725827743 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -82,6 +82,13 @@ static bool tpm_chip_req_canceled(struct tpm_chip *chip, u8 status)
 	return chip->ops->req_canceled(chip, status);
 }
 
+static bool tpm_transmit_completed(u8 status, struct tpm_chip *chip)
+{
+	u8 status_masked = status & chip->ops->req_complete_mask;
+
+	return status_masked == chip->ops->req_complete_val;
+}
+
 static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 {
 	struct tpm_header *header = buf;
@@ -106,7 +113,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 		return -E2BIG;
 	}
 
-	rc = chip->ops->send(chip, buf, count);
+	rc = chip->ops->send(chip, buf, bufsiz, count);
 	if (rc < 0) {
 		if (rc != -EPIPE)
 			dev_err(&chip->dev,
@@ -114,8 +121,19 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 		return rc;
 	}
 
-	/* A sanity check. send() should just return zero on success e.g.
-	 * not the command length.
+	/*
+	 * Synchronous devices return the response directly during the send()
+	 * call in the same buffer.
+	 */
+	if (chip->flags & TPM_CHIP_FLAG_SYNC) {
+		len = rc;
+		rc = 0;
+		goto out_sync;
+	}
+
+	/*
+	 * A sanity check. send() of asynchronous devices should just return
+	 * zero on success e.g. not the command length.
 	 */
 	if (rc > 0) {
 		dev_warn(&chip->dev,
@@ -129,8 +147,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 	stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 	do {
 		u8 status = tpm_chip_status(chip);
-		if ((status & chip->ops->req_complete_mask) ==
-		    chip->ops->req_complete_val)
+		if (tpm_transmit_completed(status, chip))
 			goto out_recv;
 
 		if (tpm_chip_req_canceled(chip, status)) {
@@ -142,6 +159,13 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 		rmb();
 	} while (time_before(jiffies, stop));
 
+	/*
+	 * Check for completion one more time, just in case the device reported
+	 * it while the driver was sleeping in the busy loop above.
+	 */
+	if (tpm_transmit_completed(tpm_chip_status(chip), chip))
+		goto out_recv;
+
 	tpm_chip_cancel(chip);
 	dev_err(&chip->dev, "Operation Timed out\n");
 	return -ETIME;
@@ -151,7 +175,10 @@ out_recv:
 	if (len < 0) {
 		rc = len;
 		dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
-	} else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
+		return rc;
+	}
+out_sync:
+	if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
 		rc = -EFAULT;
 
 	return rc ? rc : len;