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authorJens Axboe <axboe@kernel.dk>2012-07-30 09:03:10 +0200
committerJens Axboe <axboe@kernel.dk>2012-07-30 09:03:10 +0200
commit72ea1f74fcdf874cca6d2c0962379523bbd99e2c (patch)
tree4c67be6c73356086ff44ef1b8b1c9479702689ca /drivers/char/hw_random/atmel-rng.c
parentb1af9be5ef77898c05667bb9dbf3b180d91d3292 (diff)
parenta73ff3231df59a4b92ccd0dd4e73897c5822489b (diff)
Merge branch 'for-jens' of git://git.drbd.org/linux-drbd into for-3.6/drivers
Diffstat (limited to 'drivers/char/hw_random/atmel-rng.c')
-rw-r--r--drivers/char/hw_random/atmel-rng.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
index f518b99f53f5..731c9046cf7b 100644
--- a/drivers/char/hw_random/atmel-rng.c
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -34,8 +34,15 @@ static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
u32 *data = buf;
/* data ready? */
- if (readl(trng->base + TRNG_ODATA) & 1) {
+ if (readl(trng->base + TRNG_ISR) & 1) {
*data = readl(trng->base + TRNG_ODATA);
+ /*
+ ensure data ready is only set again AFTER the next data
+ word is ready in case it got set between checking ISR
+ and reading ODATA, so we don't risk re-reading the
+ same word
+ */
+ readl(trng->base + TRNG_ISR);
return 4;
} else
return 0;