The current code waits for data to be available before attempting a
second read. However the second read would not be executed as the
while loop exits.
This fix does not wait if all data has been read and reads a second
time if only partial data was retrieved on the first read.
Signed-off-by: Jorge Ramirez-Ortiz <jorge@xxxxxxxxxxxx>
---
drivers/char/hw_random/optee-rng.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/char/hw_random/optee-rng.c b/drivers/char/hw_random/optee-rng.c
index 5bc4700c4dae..967d58bb9fda 100644
--- a/drivers/char/hw_random/optee-rng.c
+++ b/drivers/char/hw_random/optee-rng.c
@@ -122,13 +122,15 @@ static int optee_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
if (max > MAX_ENTROPY_REQ_SZ)
max = MAX_ENTROPY_REQ_SZ;
- while (read == 0) {
+ for (;;) {
rng_size = get_optee_rng_data(pvt_data, data, (max - read));
data += rng_size;
read += rng_size;
if (wait && pvt_data->data_rate) {
+ if (read == max)
+ return read;
if (timeout-- == 0)
return read;
msleep((1000 * (max - read)) / pvt_data->data_rate);
--
2.17.1
