Return -E2BIG when the transfer is incomplete. The upper layer does
not retry, so not doing that is incorrect behaviour.

Cc: stable@vger.kernel.org
Fixes: a2871c62e186 ("tpm: Add support for Atmel I2C TPMs")
Signed-off-by: Jarkko Sakkinen <redacted>
---
  drivers/char/tpm/tpm_i2c_atmel.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index aa11c8a1df5e..8a7e80923091 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c

@@ -69,6 +69,10 @@ static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
  	if (status < 0)
  		return status;

+	/* The upper layer does not support incomplete sends. */
+	if (status != len)
+		return -E2BIG;
+
  	return 0;
  }