hwrng: st - Improve FIFO size/depth description

The original representation of FIFO size in the driver coupled with the
ambiguity in the documentation meant that it was easy to confuse readers.
This lead to a false positive BUG-find and subsequently time wastage
debugging this phantom issue.

Hopefully this patch can prevent future readers from falling into the
same trap.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/char/hw_random/st-rng.c b/drivers/char/hw_random/st-rng.c
index 17f0a092bf24..1d35363d23c5 100644
--- a/drivers/char/hw_random/st-rng.c
+++ b/drivers/char/hw_random/st-rng.c
@@ -29,8 +29,9 @@
 #define ST_RNG_STATUS_BAD_ALTERNANCE    BIT(1)
 #define ST_RNG_STATUS_FIFO_FULL         BIT(5)
 
-#define ST_RNG_FIFO_SIZE                8
 #define ST_RNG_SAMPLE_SIZE              2 /* 2 Byte (16bit) samples */
+#define ST_RNG_FIFO_DEPTH               4
+#define ST_RNG_FIFO_SIZE                (ST_RNG_FIFO_DEPTH * ST_RNG_SAMPLE_SIZE)
 
 /*
  * Samples are documented to be available every 0.667us, so in theory