On Fri, May 12, 2017 at 2:15 AM, PrasannaKumar Muralidharan wrote: > On 12 May 2017 at 09:47, Mike Frysinger <vapier@xxxxxxxxxx> wrote: > > From: Mike Frysinger <vapier@xxxxxxxxxxxx> > > > > If you build in hwrng & tpm-rng, but boot on a system that doesn't > > have a tpm (like via KVM), hwrng will spam the logs every 10 seconds > > with the line: > > hwrng: no data available > > > > This isn't terribly useful, so squelch the error in the ENODEV case. > > For all other errors, we still warn, and include the actual error. > > This patch removes the logging but does not fix the real problem. > Better method would be to start the hwrng_fillfn thread when first rng > provider registers and stop it when the last rng provider unregisters. what you describe is already implemented in the hw random code. the kthread only starts up when a registration happens, and will stop it when the last rng unregisters itself. the issue is that tpm-rng has registered itself here, but there aren't any tpm devices available. so it returns ENODEV. -mike