Thread (9 messages) 9 messages, 3 authors, 2016-05-24

[PATCH 4/4] hwrng: bcm2835: Read as much data as available

From: Eric Anholt <hidden>
Date: 2016-05-24 02:21:07
Also in: linux-crypto, linux-devicetree, lkml

Yendapally Reddy Dhananjaya Reddy [off-list ref]
writes:
quoted hunk ↗ jump to hunk
Read the requested number of data from the fifo

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <redacted>
---
 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);"
quoted hunk ↗ jump to hunk
@@ -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 <redacted>

Thanks!
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