commit 1005bccd7a4a ("crypto: caam - enable instantiation of all RNG4 state
handles") introduces a control when incrementing ent_delay which contains
the following comment above it:

/*
 * If either SH were instantiated by somebody else
 * (e.g. u-boot) then it is assumed that the entropy
 * parameters are properly set and thus the function
 * setting these (kick_trng(...)) is skipped.
 * Also, if a handle was instantiated, do not change
 * the TRNG parameters.
 */

This is a problem observed when sec_init() has been run in u-boot and
and TrustZone is enabled. We can fix this by instantiating all rng state
handles in u-boot but, on the Kernel side we should ensure that this
non-terminating path is dealt with.

Fixes: 1005bccd7a4a ("crypto: caam - enable instantiation of all RNG4 state
handles")

Reported-by: Ryan Harkin <ryan.har...@linaro.org>
Cc: "Horia Geantă" <horia.gea...@nxp.com>
Cc: Aymen Sghaier <aymen.sgha...@nxp.com>
Cc: Fabio Estevam <fabio.este...@nxp.com>
Cc: Peng Fan <peng....@nxp.com>
Cc: Herbert Xu <herb...@gondor.apana.org.au>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Lukas Auer <lukas.a...@aisec.fraunhofer.de>
Cc: <sta...@vger.kernel.org> # 4.12+
Signed-off-by: Bryan O'Donoghue <pure.lo...@nexus-software.ie>
---
 drivers/crypto/caam/ctrl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 98986d3..0a1e96b 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -704,7 +704,10 @@ static int caam_probe(struct platform_device *pdev)
                                         ent_delay);
                                kick_trng(pdev, ent_delay);
                                ent_delay += 400;
+                       } else if (ctrlpriv->rng4_sh_init && inst_handles) {
+                               ent_delay += 400;
                        }
+
                        /*
                         * if instantiate_rng(...) fails, the loop will rerun
                         * and the kick_trng(...) function will modfiy the
-- 
2.7.4

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