[PATCH 2/2] crypto: atmel-aes - Reset the controller before each use

From: Romain Izard
Date: Tue Oct 31 2017 - 11:26:32 EST


When using the rfc4543(gcm(aes))) mode, the registers of the hardware
engine are not empty after use. If the engine is not reset before its
next use, the following results will be invalid.

Always reset the hardware engine.

Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
---
drivers/crypto/atmel-aes.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
index 53432ab97d7e..024914e82734 100644
--- a/drivers/crypto/atmel-aes.c
+++ b/drivers/crypto/atmel-aes.c
@@ -76,12 +76,11 @@
AES_FLAGS_ENCRYPT | \
AES_FLAGS_GTAGEN)

-#define AES_FLAGS_INIT BIT(2)
#define AES_FLAGS_BUSY BIT(3)
#define AES_FLAGS_DUMP_REG BIT(4)
#define AES_FLAGS_OWN_SHA BIT(5)

-#define AES_FLAGS_PERSISTENT (AES_FLAGS_INIT | AES_FLAGS_BUSY)
+#define AES_FLAGS_PERSISTENT AES_FLAGS_BUSY

#define ATMEL_AES_QUEUE_LENGTH 50

@@ -450,11 +449,8 @@ static int atmel_aes_hw_init(struct atmel_aes_dev *dd)
if (err)
return err;

- if (!(dd->flags & AES_FLAGS_INIT)) {
- atmel_aes_write(dd, AES_CR, AES_CR_SWRST);
- atmel_aes_write(dd, AES_MR, 0xE << AES_MR_CKEY_OFFSET);
- dd->flags |= AES_FLAGS_INIT;
- }
+ atmel_aes_write(dd, AES_CR, AES_CR_SWRST);
+ atmel_aes_write(dd, AES_MR, 0xE << AES_MR_CKEY_OFFSET);

return 0;
}
--
2.14.1