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121daad8fd
linux/drivers/char
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Peter Korsgaard 121daad8fd hwrng: atmel-rng - fix race condition leading to repeated bits 
Data valid gets cleared by reading the ISR (status register) and NOT from
reading ODATA (data register). A new data word can become available between
checking ISR and reading ODATA, causing us to reuse the same data word next
time atmel_trng_read() gets called, if that happens before the following
data word is ready.

With this fixed, rngtest no longer complains of 'Continous run' errors.
Before:

rngtest -c 1000 < /dev/hwrng
rngtest 3
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO warr.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 923
rngtest: FIPS 140-2 failures: 77
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 1
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 76
rngtest: input channel speed: (min=721.402; avg=46003.510; max=49321.338)Kibitss
rngtest: FIPS tests speed: (min=11.442; avg=12.714; max=12.801)Mibits/s
rngtest: Program run time: 1931860 microseconds

After:

rngtest -c 1000 < /dev/hwrng
rngtest 3
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO warr.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 1000
rngtest: FIPS 140-2 failures: 0
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 0
rngtest: FIPS 140-2(2001-10-10) Long run: 0
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=777.518; avg=36988.482; max=43115.342)Kibitss
rngtest: FIPS tests speed: (min=11.951; avg=12.715; max=12.887)Mibits/s
rngtest: Program run time: 2035543 microseconds

Cc: stable@vger.kernel.org
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Reported-by: George Pontis <GPontis@z9.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2012-05-31 20:53:08 +10:00
..
agp Merge remote-tracking branch 'airlied/drm-fixes' into drm-intel-next-queued 2012-02-10 17:14:49 +01:00
hw_random hwrng: atmel-rng - fix race condition leading to repeated bits 2012-05-31 20:53:08 +10:00
ipmi module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
mwave Fix common misspellings 2011-03-31 11:26:23 -03:00
pcmcia TTY: remove unneeded tty->index checks 2012-03-08 11:42:21 -08:00
tpm Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-03-21 13:25:04 -07:00
xilinx_hwicap treewide: Convert uses of struct resource to resource_size(ptr) 2011-06-10 14:55:36 +02:00
apm-emulation.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-10-25 12:11:02 +02:00
applicom.c
applicom.h
bfin-otp.c
bsr.c treewide: Convert uses of struct resource to resource_size(ptr) 2011-06-10 14:55:36 +02:00
ds1302.c
ds1620.c
dsp56k.c
dtlk.c
efirtc.c
generic_nvram.c drivers: fix up various ->llseek() implementations 2011-07-20 20:47:58 -04:00
genrtc.c
hangcheck-timer.c
hpet.c Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-07-22 17:05:15 -07:00
i8k.c module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
Kconfig tty: delete briq_panel.c driver 2012-03-08 10:45:55 -08:00
lp.c module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
Makefile tty: delete briq_panel.c driver 2012-03-08 10:45:55 -08:00
mbcs.c
mbcs.h Fix common misspellings 2011-03-31 11:26:23 -03:00
mem.c switch device_get_devnode() and ->devnode() to umode_t * 2012-01-03 22:54:55 -05:00
misc.c switch device_get_devnode() and ->devnode() to umode_t * 2012-01-03 22:54:55 -05:00
mmtimer.c posix-timers: Cleanup namespace 2011-02-02 15:28:19 +01:00
msm_smd_pkt.c drivers/char/msm_smd_pkt.c: don't use IS_ERR() 2011-08-25 16:25:33 -07:00
mspec.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
nsc_gpio.c
nvram.c drivers/char: comment fix: CMOS RTC update code is now in kernel/time/ntp.c 2012-02-03 22:50:56 +01:00
nwbutton.c Fix common misspellings 2011-03-31 11:26:23 -03:00
nwbutton.h
nwflash.c module_param: make bool parameters really bool (drivers & misc) 2012-01-13 09:32:20 +10:30
pc8736x_gpio.c
ppdev.c drivers/char/ppdev.c: put gotten port value 2011-05-26 17:12:37 -07:00
ps3flash.c drivers/char: Add module.h to those who were using it implicitly 2011-10-31 19:31:40 -04:00
ramoops.c char/ramoops: included linux/err.h twice 2012-02-24 14:16:43 -08:00
random.c Merge branch 'x86/rdrand' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-01-16 18:23:09 -08:00
raw.c switch device_get_devnode() and ->devnode() to umode_t * 2012-01-03 22:54:55 -05:00
rtc.c drivers/char: comment fix: CMOS RTC update code is now in kernel/time/ntp.c 2012-02-03 22:50:56 +01:00
scx200_gpio.c
snsc_event.c
snsc.c
snsc.h headers: kobject.h redux 2011-01-10 08:51:44 -08:00
sonypi.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tb0219.c
tile-srom.c switch device_get_devnode() and ->devnode() to umode_t * 2012-01-03 22:54:55 -05:00
tlclk.c char: Fix typo in tlclk.c 2012-02-09 23:09:37 +01:00
toshiba.c
ttyprintk.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
uv_mmtimer.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
virtio_console.c virtio: console: Disable callbacks for virtqueues at start of S4 freeze 2012-01-12 15:44:45 +10:30