[ 04/48] hwrng: atmel-rng - fix data valid check

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

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

From: Peter Korsgaard <jacmet@xxxxxxxxxx>

commit c475c06f4bb689d6ad87d7512e036d6dface3160 upstream.

Brown paper bag: Data valid is LSB of the ISR (status register), and NOT
of ODATA (current random data word)!

With this, rngtest is a lot happier. Before:

rngtest 3
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO warr.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 3
rngtest: FIPS 140-2 failures: 997
rngtest: FIPS 140-2(2001-10-10) Monobit: 604
rngtest: FIPS 140-2(2001-10-10) Poker: 996
rngtest: FIPS 140-2(2001-10-10) Runs: 36
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 117
rngtest: input channel speed: (min=622.371; avg=23682.481; max=28224.350)Kibitss
rngtest: FIPS tests speed: (min=12.361; avg=12.718; max=12.861)Mibits/s
rngtest: Program run time: 2331696 microsecondsx

After:
rngtest 3
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO warr.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 999
rngtest: FIPS 140-2 failures: 1
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 1
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=777.363; avg=43588.270; max=47870.711)Kibitss
rngtest: FIPS tests speed: (min=11.943; avg=12.716; max=12.844)Mibits/s
rngtest: Program run time: 1955282 microseconds

Signed-off-by: Peter Korsgaard <jacmet@xxxxxxxxxx>
Reported-by: George Pontis <GPontis@xxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/char/hw_random/atmel-rng.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
index 6289f0e..731c904 100644
--- a/drivers/char/hw_random/atmel-rng.c
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -34,7 +34,7 @@ static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
 	u32 *data = buf;
 
 	/* data ready? */
-	if (readl(trng->base + TRNG_ODATA) & 1) {
+	if (readl(trng->base + TRNG_ISR) & 1) {
 		*data = readl(trng->base + TRNG_ODATA);
 		/*
 		  ensure data ready is only set again AFTER the next data


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