On Fri, Jun 28, 2019 at 5:42 PM Mark Rutland <mark.rutland@xxxxxxx> wrote: > > On Wed, Jun 12, 2019 at 12:33:02PM +0800, Hsin-Yi Wang wrote: > > Adding "rng-seed" to dtb. It's fine to add this property if original > > fdt doesn't contain it. Since original seed will be wiped after > > read, so use a default size 128 bytes here. > > Why is 128 bytes the default value? More than 64 bytes should be enough. > > I didn't see an update to Documentation/devicetree/bindings/chosen.txt, > so it's not clear to me precisely what we expect. > Rob suggested to update in a newer dt-schema documentation at https://github.com/devicetree-org/dt-schema. A pull request has been sent but perhaps it would continue if kernel patches are accepted. > > For 128 bytes, it would be better to use a buffer on the stack. That > avoids the possibility of the allocation failing. > Okay, I'll update this. > > If the RNG wasn't initialised, we'd carry on with a warning. Why do we > follow a different policy here? > For failure case, I think kernel can still be boot since this is not a very fatal case, just same as the seed wasn't provided by bootloader at first boot. So I'll also let fdt_setprop() failed case carry on with warning. Thanks
