Hi Mark, On Fri, Apr 08, 2022 at 07:33:53PM +0100, Mark Rutland wrote: > On Fri, Apr 08, 2022 at 08:21:42PM +0200, Jason A. Donenfeld wrote: > > In the event that random_get_entropy() can't access a cycle counter or > > similar, falling back to returning 0 is really not the best we can do. > > Instead, at least calling sched_clock() would be preferable, because > > that always needs to return _something_, even falling back to jiffies > > eventually. It's not as though sched_clock() is super high precision or > > guaranteed to be entropic, but basically anything that's not zero all > > the time is better than returning zero all the time. > > > > If CONFIG_ARM_ARCH_TIMER=n, then get_cycles() will return 0, so we only > > need the fallback code for that case. > > In arch/arm64/Kconfig we unconditionally select CONFIG_ARM_ARCH_TIMER, > so that configuration shouldn't be possible, and I don't think this > patch is necessary. > > On arm64 we depend on the architected timer in a bunch of places, so > anyone hacking that out has bigger problems. Thanks for the tip. I'll drop this patch from the series. Jason