Re: [PATCH] crypto: caam - adjust RNG timing to support more devices
From: Bastian Krause
Date: Tue Jul 18 2023 - 05:43:21 EST
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:
--
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