[PATCH 1/4] n2rng: limit error spewage when self-test fails

From: Shannon Nelson
Date: Thu Jan 12 2017 - 13:53:39 EST


If the self-test fails, it probably won't actually suddenly
start working. Currently, this causes an endless spew of
error messages on the console and in the logs, so this patch
adds a limiter to the test.

Reported-by: Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx>
Signed-off-by: Shannon Nelson <shannon.nelson@xxxxxxxxxx>
---
drivers/char/hw_random/n2-drv.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 3b06c1d..102560f 100644
--- a/drivers/char/hw_random/n2-drv.c
+++ b/drivers/char/hw_random/n2-drv.c
@@ -589,6 +589,7 @@ static void n2rng_work(struct work_struct *work)
{
struct n2rng *np = container_of(work, struct n2rng, work.work);
int err = 0;
+ static int retries = 4;

if (!(np->flags & N2RNG_FLAG_CONTROL)) {
err = n2rng_guest_check(np);
@@ -606,7 +607,9 @@ static void n2rng_work(struct work_struct *work)
dev_info(&np->op->dev, "RNG ready\n");
}

- if (err && !(np->flags & N2RNG_FLAG_SHUTDOWN))
+ if (--retries == 0)
+ dev_err(&np->op->dev, "Self-test retries failed, RNG not ready\n");
+ else if (err && !(np->flags & N2RNG_FLAG_SHUTDOWN))
schedule_delayed_work(&np->work, HZ * 2);
}

--
1.7.1