* b43: /dev/hwrng isn't random
@ 2013-02-06 4:47 Christian Kujau
0 siblings, 0 replies; 2+ messages in thread
From: Christian Kujau @ 2013-02-06 4:47 UTC (permalink / raw)
To: b43-dev
Hi,
while playing around with this BCM4306 (b43) wifi NIC (and reporting some
lockdep issues, [0]), I noticed that the chip could be used as a HWRNG and
driver support for this has been added years ago - great, I never knew!
But when attempting to read from /dev/hwrng (b43 is loaded, interface is
up & running), the device returns not random bytes, but:
$ head -c 1000 /dev/hwrng | od -x
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
0001740 0000 0000 0000 0000
0001750
I've used a custom-built 3.8-rc6 and a stock Debian 3.2.0-4, same results.
I should add that this BCM4306 wifi NIC is inside an older (2005)
PowerBook G4 laptop, so maybe it's a hardware fault. However, wifi is
working perfectly.
I found a similar thing reported _years_ ago for the OLTP project, with
the following note, though I could not find the exact changeset for the
fix yet:
https://dev.laptop.org/ticket/8089#comment:4
> Turned out OFW wasn't turning on the AES module.
CONFIG_CRYPTO_AES is enabled in my case. On another box with an BCM4312
chip (and a Fedora 3.7.2-204.fc18.i686 kernel) the hwrng is working.
More details, .config & lspci here:
http://nerdbynature.de/bits/3.8.0-rc6/BCM4306/
http://nerdbynature.de/bits/3.8.0-rc6/BCM4312/
Any thoughts how to find out if this is a software or a hardware issue?
Thanks,
Christian.
[0] http://www.spinics.net/lists/kernel/msg1477153.html
--
BOFH excuse #144:
Too few computrons available.
^ permalink raw reply [flat|nested] 2+ messages in thread
* b43: /dev/hwrng isn't random
@ 2013-02-08 1:28 Christian Kujau
0 siblings, 0 replies; 2+ messages in thread
From: Christian Kujau @ 2013-02-08 1:28 UTC (permalink / raw)
To: LKML
forwarding to lkml, not sure how many people read b43-dev...
Hi,
while playing around with this BCM4306 (b43) wifi NIC (and reporting some
lockdep issues, [0]), I noticed that the chip could be used as a HWRNG and
driver support for this has been added years ago - great, I never knew!
But when attempting to read from /dev/hwrng (b43 is loaded, interface is
up & running), the device returns not random bytes, but:
$ head -c 1000 /dev/hwrng | od -x
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
0001740 0000 0000 0000 0000
0001750
I've used a custom-built 3.8-rc6 and a stock Debian 3.2.0-4, same results.
I should add that this BCM4306 wifi NIC is inside an older (2005)
PowerBook G4 laptop, so maybe it's a hardware fault. However, wifi is
working perfectly.
I found a similar thing reported _years_ ago for the OLTP project, with
the following note, though I could not find the exact changeset for the
fix yet:
https://dev.laptop.org/ticket/8089#comment:4
> Turned out OFW wasn't turning on the AES module.
CONFIG_CRYPTO_AES is enabled in my case. On another box with an BCM4312
chip (and a Fedora 3.7.2-204.fc18.i686 kernel) the hwrng is working.
More details, .config & lspci here:
http://nerdbynature.de/bits/3.8.0-rc6/BCM4306/
http://nerdbynature.de/bits/3.8.0-rc6/BCM4312/
Any thoughts how to find out if this is a software or a hardware issue?
Thanks,
Christian.
[0] http://www.spinics.net/lists/kernel/msg1477153.html
--
BOFH excuse #144:
Too few computrons available.
^ permalink raw reply [flat|nested] 2+ messages in thread
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