diff options
Diffstat (limited to 'drivers/char/hw_random/omap-rng.c')
| -rw-r--r-- | drivers/char/hw_random/omap-rng.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c index 74d11ae6abe9..091753765d99 100644 --- a/drivers/char/hw_random/omap-rng.c +++ b/drivers/char/hw_random/omap-rng.c @@ -66,6 +66,13 @@ #define OMAP4_RNG_OUTPUT_SIZE 0x8 #define EIP76_RNG_OUTPUT_SIZE 0x10 +/* + * EIP76 RNG takes approx. 700us to produce 16 bytes of output data + * as per testing results. And to account for the lack of udelay()'s + * reliability, we keep the timeout as 1000us. + */ +#define RNG_DATA_FILL_TIMEOUT 100 + enum { RNG_OUTPUT_0_REG = 0, RNG_OUTPUT_1_REG, @@ -175,7 +182,7 @@ static int omap_rng_do_read(struct hwrng *rng, void *data, size_t max, if (max < priv->pdata->data_size) return 0; - for (i = 0; i < 20; i++) { + for (i = 0; i < RNG_DATA_FILL_TIMEOUT; i++) { present = priv->pdata->data_present(priv); if (present || !wait) break; @@ -442,6 +449,7 @@ static int omap_rng_probe(struct platform_device *pdev) priv->rng.read = omap_rng_do_read; priv->rng.init = omap_rng_init; priv->rng.cleanup = omap_rng_cleanup; + priv->rng.quality = 900; priv->rng.priv = (unsigned long)priv; platform_set_drvdata(pdev, priv); |