hwrng: n2 - limit error spewage when self-test fails

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.

Orabug: 25127795

Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit db602a7f940a71870c17e39bcbe4e4d7a4a8273e)
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 3b06c1d6cfb280a18bd13716bfdbf2c38fa085ed..102560ffed44a036225e3522b9f2e154c0d0ca56 100644 (file)
--- 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);
 }