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@foundries.io --- 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);