Hi Heinrich, On Sun, 5 Nov 2023 at 03:47, Heinrich Schuchardt <heinrich.schucha...@canonical.com> wrote: > > On 11/4/23 21:42, Simon Glass wrote: > > Hi Heinrich, > > > > On Sat, 4 Nov 2023 at 06:51, Heinrich Schuchardt > > <heinrich.schucha...@canonical.com> wrote: > >> > >> The existence of devices should be checked in the bind method and not in > >> the probe method. Adjust the RISC-V Zkr RNG driver accordingly. > >> > >> Use ENOENT (and not ENODEV) to signal that the device is not available. > >> > >> Fixes: ceec977ba1a9 ("rng: Provide a RNG based on the RISC-V Zkr ISA > >> extension") > >> Reported-by: Andre Przywara <andre.przyw...@arm.com> > >> Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com> > >> --- > >> drivers/rng/riscv_zkr_rng.c | 34 ++++++++++++++++++++++++++-------- > >> 1 file changed, 26 insertions(+), 8 deletions(-) > > > > This device should be in the DT, so you have some control over which > > RNG is used. > > The device-tree provided by QEMU does not contain such a device as Zkr > is an ISA extension and not a device. This device-tree is not under the > control of the U-Boot project.
Why do you bring up QEMU? I would expect that it follows the norma dt bindings, so it should not be any different from real hardware? Anyway, you could add it. It is just a binding. I believe RISC-V has all sorts of isa options which result in different machine features. What are you going to do when you want to choose between the ISA RNG and a TPM one? Regards, Simon