linux-kernel - [PATCH v2 3/3] hwrng: st: Improve FIFO size/depth description

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1444220609-31251-4-git-send-email-lee.jones@linaro.org>
Date:	Wed,  7 Oct 2015 13:23:29 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc:	kernel@...inux.com, herbert@...dor.apana.org.au,
	linux-crypto@...r.kernel.org, pankaj.dev@...com,
	daniel.thompson@...aro.org, linux@....linux.org.uk,
	Lee Jones <lee.jones@...aro.org>
Subject: [PATCH v2 3/3] hwrng: st: Improve FIFO size/depth description

The original representation of FIFO size in the driver coupled with the
ambiguity in the documentation meant that it was easy to confuse readers.
This lead to a false positive BUG-find and subsequently time wastage
debugging this phantom issue.

Hopefully this patch can prevent future readers from falling into the
same trap.

Signed-off-by: Lee Jones <lee.jones@...aro.org>
---
 drivers/char/hw_random/st-rng.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/char/hw_random/st-rng.c b/drivers/char/hw_random/st-rng.c
index 17f0a09..1d35363 100644
--- a/drivers/char/hw_random/st-rng.c
+++ b/drivers/char/hw_random/st-rng.c
@@ -29,8 +29,9 @@
 #define ST_RNG_STATUS_BAD_ALTERNANCE	BIT(1)
 #define ST_RNG_STATUS_FIFO_FULL		BIT(5)
 
-#define ST_RNG_FIFO_SIZE		8
 #define ST_RNG_SAMPLE_SIZE		2 /* 2 Byte (16bit) samples */
+#define ST_RNG_FIFO_DEPTH		4
+#define ST_RNG_FIFO_SIZE		(ST_RNG_FIFO_DEPTH * ST_RNG_SAMPLE_SIZE)
 
 /*
  * Samples are documented to be available every 0.667us, so in theory
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/