3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Horia Geantă <[email protected]>

commit 225ece3e7dad4cfc44cca38ce7a3a80f255ea8f1 upstream.

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.

Fixes: 1005bccd7a4a6 ("crypto: caam - enable instantiation of all RNG4 state 
handles")
Reported-by: Bryan O'Donoghue <[email protected]>
Suggested-by: Auer Lukas <[email protected]>
Signed-off-by: Horia Geantă <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <[email protected]>
---
 drivers/crypto/caam/ctrl.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -196,12 +196,16 @@ static int instantiate_rng(struct device
                 * without any error (HW optimizations for later
                 * CAAM eras), then try again.
                 */
+               if (ret)
+                       break;
+
                rdsta_val =
                        rd_reg32(&topregs->ctrl.r4tst[0].rdsta) & RDSTA_IFMASK;
-               if (status || !(rdsta_val & (1 << sh_idx)))
+               if (status || !(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 */

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