fix(st-crypto): do not read RNG data if it's not ready
Having RNG_SR_DRDY bit in RNG_SR register does not mean that there are 4
RNG words ready to be read. Add a check on RNG_SR_DRDY between each word
reading.
Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Change-Id: I46af7ca6c0ddbe19540b248365a5016b15b9a707
diff --git a/drivers/st/crypto/stm32_rng.c b/drivers/st/crypto/stm32_rng.c
index a9dc43f..1342fd4 100644
--- a/drivers/st/crypto/stm32_rng.c
+++ b/drivers/st/crypto/stm32_rng.c
@@ -187,6 +187,10 @@
count = 4U;
while (len != 0U) {
+ if ((mmio_read_32(stm32_rng.base + RNG_SR) & RNG_SR_DRDY) == 0U) {
+ break;
+ }
+
data32 = mmio_read_32(stm32_rng.base + RNG_DR);
count--;