In case DECO0 cannot be acquired - i.e. run_descriptor_deco0() fails
with -ENODEV, caam_probe() enters an endless loop:

run_descriptor_deco0
        ret -ENODEV
        -> instantiate_rng
                -ENODEV, overwritten by -EAGAIN
                ret -EAGAIN
                -> caam_probe
                        -EAGAIN results in endless loop

It turns out the error path in instantiate_rng() is incorrect,
the checks are done in the wrong order.

Cc: <sta...@vger.kernel.org> # 3.13+
Fixes: 1005bccd7a4a6 ("crypto: caam - enable instantiation of all RNG4 state 
handles")
Reported-by: Bryan O'Donoghue <pure.lo...@nexus-software.ie>
Suggested-by: Auer Lukas <lukas.a...@aisec.fraunhofer.de>
Signed-off-by: Horia Geantă <horia.gea...@nxp.com>
---
 drivers/crypto/caam/ctrl.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 75d280cb2dc0..e843cf410373 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -228,12 +228,16 @@ static int instantiate_rng(struct device *ctrldev, int 
state_handle_mask,
                 * without any error (HW optimizations for later
                 * CAAM eras), then try again.
                 */
+               if (ret)
+                       break;
+
                rdsta_val = rd_reg32(&ctrl->r4tst[0].rdsta) & RDSTA_IFMASK;
                if ((status && status != JRSTA_SSRC_JUMP_HALT_CC) ||
-                   !(rdsta_val & (1 << sh_idx)))
+                   !(rdsta_val & (1 << sh_idx))) {
                        ret = -EAGAIN;
-               if (ret)
                        break;
+               }
+
                dev_info(ctrldev, "Instantiated RNG4 SH%d\n", sh_idx);
                /* Clear the contents before recreating the descriptor */
                memset(desc, 0x00, CAAM_CMD_SZ * 7);
-- 
2.12.0.264.gd6db3f216544

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