| Message ID | 1464020451-16520-5-git-send-email-yendapally.reddy@broadcom.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Herbert Xu |
| Headers | show |
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@broadcom.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_random/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 *buf, size_t max, > bool wait) > { > void __iomem *rng_base = (void __iomem *)rng->priv; > + u32 max_words = 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 *buf, size_t max, > cpu_relax(); > } > > - *(u32 *)buf = __raw_readl(rng_base + RNG_DATA); > - return sizeof(u32); > + num_words = (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!
diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/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 *buf, size_t max, bool wait) { void __iomem *rng_base = (void __iomem *)rng->priv; + u32 max_words = max/sizeof(u32); + u32 num_words, count; while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) { if (!wait) @@ -50,8 +52,14 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, cpu_relax(); } - *(u32 *)buf = __raw_readl(rng_base + RNG_DATA); - return sizeof(u32); + num_words = (readl(rng_base + RNG_STATUS) >> 24); + if (num_words > max_words) + num_words = max_words; + + for (count = 0; count < num_words; count++) + ((u32 *)buf)[count] = readl(rng_base + RNG_DATA); + + return (num_words * sizeof(u32)); } static struct hwrng bcm2835_rng_ops = {
Read the requested number of data from the fifo Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> --- drivers/char/hw_random/bcm2835-rng.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)