[PATCH] crypto: atmel-sha204a - Fix error codes in OTP reads

[Thorsten Blum]

Return -EINVAL from atmel_i2c_init_read_otp_cmd() on invalid addresses
instead of -1. Since the OTP zone is accessed in 4-byte blocks, valid
addresses range from 0 to OTP_ZONE_SIZE / 4 - 1. Fix the bounds check
accordingly.

In atmel_sha204a_otp_read(), propagate the actual error code from
atmel_i2c_init_read_otp_cmd() instead of -1. Also, return -EIO instead
of -EINVAL when the device is not ready.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: e05ce444e9e5 ("crypto: atmel-sha204a - add reading from otp zone")
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx>
---
Compile-tested only.
---
 drivers/crypto/atmel-i2c.c     | 4 ++--
 drivers/crypto/atmel-sha204a.c | 7 ++++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 9688d116d07e..ba9d3f593601 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -72,8 +72,8 @@ EXPORT_SYMBOL(atmel_i2c_init_read_config_cmd);
 
 int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr)
 {
-	if (addr < 0 || addr > OTP_ZONE_SIZE)
-		return -1;
+	if (addr >= OTP_ZONE_SIZE / 4)
+		return -EINVAL;
 
 	cmd->word_addr = COMMAND;
 	cmd->opcode = OPCODE_READ;
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 0fcf4a39de27..6b4e2764523e 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -94,9 +94,10 @@ static int atmel_sha204a_rng_read(struct hwrng *rng, void *data, size_t max,
 static int atmel_sha204a_otp_read(struct i2c_client *client, u16 addr, u8 *otp)
 {
 	struct atmel_i2c_cmd cmd;
-	int ret = -1;
+	int ret;
 
-	if (atmel_i2c_init_read_otp_cmd(&cmd, addr) < 0) {
+	ret = atmel_i2c_init_read_otp_cmd(&cmd, addr);
+	if (ret < 0) {
 		dev_err(&client->dev, "failed, invalid otp address %04X\n",
 			addr);
 		return ret;
@@ -106,7 +107,7 @@ static int atmel_sha204a_otp_read(struct i2c_client *client, u16 addr, u8 *otp)
 
 	if (cmd.data[0] == 0xff) {
 		dev_err(&client->dev, "failed, device not ready\n");
-		return -EINVAL;
+		return -EIO;
 	}
 
 	memcpy(otp, cmd.data+1, 4);
-- 
Thorsten Blum <thorsten.blum@xxxxxxxxx>
GPG: 1D60 735E 8AEF 3BE4 73B6  9D84 7336 78FD 8DFE EAD4