Messages in this thread Patch in this message | | | From | George Spelvin <> | Date | Wed, 20 Mar 2019 22:50:00 -0400 | Subject | [RFC PATCH v1 26/50] drivers/nfc/nfcsim: use prandom_32() for time delay |
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get_random_bytes() is expensive crypto-quality seed material. That's not needed for a simple simulation.
(Also, a 3-10 ms delay, when converted to jiffies, isn't a lot of granularity. It's 1 jiffy at HZ=100 and 3 jiffies at HZ=250 or HZ=300.)
Signed-off-by: George Spelvin <lkml@sdf.org> Cc: Thierry Escande <thierry.escande@collabora.com> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: linux-nfc@lists.01.org --- drivers/nfc/nfcsim.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/nfc/nfcsim.c b/drivers/nfc/nfcsim.c index a9864fcdfba6b..eb0a909a25487 100644 --- a/drivers/nfc/nfcsim.c +++ b/drivers/nfc/nfcsim.c @@ -229,8 +229,7 @@ static int nfcsim_send(struct nfc_digital_dev *ddev, struct sk_buff *skb, dev->mode); /* Add random delay (between 3 and 10 ms) before sending data */ - get_random_bytes(&delay, 1); - delay = 3 + (delay & 0x07); + delay = 3 + prandom_u32_max(8); schedule_delayed_work(&dev->send_work, msecs_to_jiffies(delay)); } -- 2.26.0
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