On 11/5/23 18:25, Simon Glass wrote:
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?
Yes Simon, QEMU follows the normal bindings. If you want to change
these, please, contribute to the RISC-V working groups or to the Linux
kernel project.
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?
First of all there are different configurations switches for both
drivers. But of course you can enable both. They will be different
U-Boot devices. The rng command has a parameter to choose a RNG device
by device number. This is not different to having two USB drives.
Best regards
Heinrich
