Re: [PATCH] hw_random: atmel-rng: fix data valid check

[Nicolas Ferre <nicolas.ferre@atmel.com>]

On 05/23/2012 02:31 PM, Peter Korsgaard :
> 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
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
> Reported-by: George Pontis <GPontis@z9.com>

Indeed, yes ;-)

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

> ---
>  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 f518b99..d7ab920 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);
>  		return 4;
>  	} else


-- 
Nicolas Ferre