lib: uuid: fix the test on RNG device presence

Correct the test on RNG device presence,when ret is equal to 0,
before to call dm_rng_read function.

Without this patch the RNG device is not used when present (when ret == 0)
or a data abort occurs in dm_rng_read when CONFIG_DM_RNG is activated but
the RNG device is not present in device tree (ret != 0 and devp = NULL).

Fixes: 92fdad28cfdf ("lib: uuid: use RNG device if present")
CC: Matthias Brugger <mbrugger@suse.com>
CC: Torsten Duwe <duwe@suse.de>
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/lib/uuid.c b/lib/uuid.c
index 67267c6..e4703dc 100644 (file)
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -257,7 +257,7 @@ void gen_rand_uuid(unsigned char *uuid_bin)
 
        if (IS_ENABLED(CONFIG_DM_RNG)) {
                ret = uclass_get_device(UCLASS_RNG, 0, &devp);
-               if (ret) {
+               if (!ret) {
                        ret = dm_rng_read(devp, &randv, sizeof(randv));
                        if (ret < 0)
                                randv = 0;