From: Eric Anholt <eric@anholt.net>
Subject: Re: [PATCH 4/4] hwrng: bcm2835: Read as much data as available
Date: Mon, 23 May 2016 19:21:00 -0700
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	Yendapally Reddy Dhananjaya Reddy
	<yendapally.reddy@broadcom.com>
To: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>,
	Rob Herring <robh+dt@kernel.org>,
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	Russell King <linux@arm.linux.org.uk>,
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Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
writes:

> Read the requested number of data from the fifo
>
> Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadc=
om.com>
> ---
>  drivers/char/hw_random/bcm2835-rng.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_rando=
m/bcm2835-rng.c
> index b1e8b78..9bbdc07 100644
> --- a/drivers/char/hw_random/bcm2835-rng.c
> +++ b/drivers/char/hw_random/bcm2835-rng.c
> @@ -43,6 +43,8 @@ static int bcm2835_rng_read(struct hwrng *rng, void *bu=
f, size_t max,
>  			       bool wait)
>  {
>  	void __iomem *rng_base =3D (void __iomem *)rng->priv;
> +	u32 max_words =3D max/sizeof(u32);

Style fix: Binary operators get a space on each side, so
"max / sizeof(u32);"

> @@ -50,8 +52,14 @@ static int bcm2835_rng_read(struct hwrng *rng, void *b=
uf, size_t max,
>  		cpu_relax();
>  	}
>=20=20
> -	*(u32 *)buf =3D __raw_readl(rng_base + RNG_DATA);
> -	return sizeof(u32);
> +	num_words =3D (readl(rng_base + RNG_STATUS) >> 24);

Optional cleanup: here and in the return statement, drop the extra
parenthesis.

Functionality-wise, this patch looks great to me, and should make the
driver more efficient.  With at least the binary operators change done,
it will be:

Reviewed-by: Eric Anholt <eric@anholt.net>

Thanks!

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