Re: [PATCH] crypto: caam - adjust RNG timing to support more devices

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 7/17/23 14:43, Bastian Krause wrote:
On 6/12/23 10:26, meenakshi.aggarwal@xxxxxxx wrote:
From: Victoria Milhoan <vicki.milhoan@xxxxxxxxxxxxx>

Adjust RNG timing parameters to support more i.MX6 devices.

Signed-off-by: Victoria Milhoan <vicki.milhoan@xxxxxxxxxxxxx>
Signed-off-by: Dan Douglass <dan.douglass@xxxxxxx>
Signed-off-by: Vipul Kumar <vipul_kumar@xxxxxxxxxx>
Signed-off-by: Horia Geantă <horia.geanta@xxxxxxx>
---
  drivers/crypto/caam/ctrl.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

This patch seems to breaks CAAM RNG instantiation on an i.MX8MM at my end:

caam 30900000.crypto: Entropy delay = 3200
caam 30900000.crypto: Entropy delay = 3600
[...]
caam 30900000.crypto: Entropy delay = 12400
caam 30900000.crypto: failed to instantiate RNG
caam: probe of 30900000.crypto failed with error -11

If I revert this patch or increase RTSDCTL_ENT_DLY_MAX to a value > 66800, it works again:

caam 30900000.crypto: Entropy delay = 32800
caam 30900000.crypto: Entropy delay = 33200
[...]
caam 30900000.crypto: Entropy delay = 66800
caam 30900000.crypto: Instantiated RNG4 SH0
caam 30900000.crypto: Instantiated RNG4 SH1
caam 30900000.crypto: device ID = 0x0a16040100000000 (Era 9)
caam 30900000.crypto: job rings = 2, qi = 0
caam algorithms registered in /proc/crypto
caam 30900000.crypto: caam pkc algorithms registered in /proc/crypto
caam 30900000.crypto: registering rng-caam
Executing RNG SELF-TEST with wait
random: crng init done
caam 30900000.crypto: rng crypto API alg registered prng-caam

This ^ was the kernel log for..


--- a/drivers/crypto/caam/regs.h
+++ b/drivers/crypto/caam/regs.h
@@@ -522,7 -522,7 +522,7 @@@ struct rng4tst
  #define RTSDCTL_ENT_DLY_SHIFT 16
  #define RTSDCTL_ENT_DLY_MASK (0xffff << RTSDCTL_ENT_DLY_SHIFT)
  #define RTSDCTL_ENT_DLY_MIN 3200
--#define RTSDCTL_ENT_DLY_MAX 12800
++#define RTSDCTL_ENT_DLY_MAX 70000
  #define RTSDCTL_SAMP_SIZE_MASK 0xffff
  #define RTSDCTL_SAMP_SIZE_VAL 512
        u32 rtsdctl;            /* seed control register */


For completion's sake: Reverting this patch..


--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -383,7 +383,7 @@ static void kick_trng(struct device *dev, int ent_delay)
                /* min. freq. count, equal to 1/4 of the entropy sample length */
                wr_reg32(&r4tst->rtfrqmin, val >> 2);
                /* max. freq. count, equal to 16 times the entropy sample length */
-               wr_reg32(&r4tst->rtfrqmax, val << 4);
+               wr_reg32(&r4tst->rtfrqmax, RTFRQMAX_DISABLE);
        }
wr_reg32(&r4tst->rtsdctl, (val << RTSDCTL_ENT_DLY_SHIFT) |


..produces this kernel log (without RNG SELF-TEST):

caam 30900000.crypto: Entropy delay = 3200
caam 30900000.crypto: Entropy delay = 3600
caam 30900000.crypto: Instantiated RNG4 SH0
caam 30900000.crypto: Instantiated RNG4 SH1
caam 30900000.crypto: device ID = 0x0a16040100000000 (Era 9)
caam 30900000.crypto: job rings = 2, qi = 0
caam algorithms registered in /proc/crypto
caam 30900000.crypto: caam pkc algorithms registered in /proc/crypto
caam 30900000.crypto: registering rng-caam
caam 30900000.crypto: rng crypto API alg registered prng-caam
random: crng init done

Regards,
Bastian


diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 5fed3cf354c0..62dd069942e4 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -383,8 +383,8 @@ static void kick_trng(struct device *dev, int ent_delay)
      wr_reg32(&r4tst->rtsdctl, val);
      /* min. freq. count, equal to 1/4 of the entropy sample length */
      wr_reg32(&r4tst->rtfrqmin, ent_delay >> 2);
-    /* disable maximum frequency count */
-    wr_reg32(&r4tst->rtfrqmax, RTFRQMAX_DISABLE);
+    /* max. freq. count, equal to 16 times the entropy sample length */
+    wr_reg32(&r4tst->rtfrqmax, ent_delay << 4);
      /* read the control register */
      val = rd_reg32(&r4tst->rtmctl);
  start_rng:


--
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |




[Index of Archives]     [Kernel]     [Gnu Classpath]     [Gnu Crypto]     [DM Crypt]     [Netfilter]     [Bugtraq]
  Powered by Linux