commit 442601e87a4769a8daba4976ec3afa5222ca211d upstream
Return -E2BIG when the transfer is incomplete. The upper layer does
not retry, so not doing that is incorrect behaviour.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: a2871c62e186 ("tpm: Add support for Atmel I2C TPMs")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
---
backport v4.9.99
drivers/char/tpm/tpm_i2c_atmel.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index 95ce2e9ccdc6..cc4e642d3180 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c
@@ -65,7 +65,15 @@ static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
dev_dbg(&chip->dev,
"%s(buf=%*ph len=%0zx) -> sts=%d\n", __func__,
(int)min_t(size_t, 64, len), buf, len, status);
- return status;
+
+ if (status < 0)
+ return status;
+
+ /* The upper layer does not support incomplete sends. */
+ if (status != len)
+ return -E2BIG;
+
+ return 0;
}
static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
--
2.20.1
