[PATCH 3/3] cmd: rng: Add rng list command

[Weizhao Ouyang]

On Thu, Jan 25, 2024 at 10:49 PM Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 25.01.24 15:05, Weizhao Ouyang wrote:
> > Add rng list command to list all probed RNG device.
>
> Thank you for your contribution.
>
> Would the following be more accurate?
>
> The 'rng list' command probes all RNG devices and list those devices
> that are successfully probed.

Yeah.

>
> >
> > Signed-off-by: Weizhao Ouyang <o451686892 at gmail.com>
> > ---
> >   cmd/rng.c | 15 +++++++++++++++
> >   1 file changed, 15 insertions(+)
> >
> > diff --git a/cmd/rng.c b/cmd/rng.c
> > index 52f722c7af..4818133f94 100644
> > --- a/cmd/rng.c
> > +++ b/cmd/rng.c
> > @@ -18,6 +18,19 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> >       int devnum;
> >       struct udevice *dev;
> >       int ret = CMD_RET_SUCCESS;
> > +     int idx;
>
> Please, put the definition into the code block where it is used.

Sorry I imported the draft code, will remove it in the next version.

>
> > +
> > +     if (argc == 2 && !strcmp(argv[1], "list")) {
>
> int idx = 0;
>
> > +             uclass_foreach_dev_probe(UCLASS_RNG, dev) {
> > +                     printf("RNG #%d - %s\n", dev->seq_, dev->name);
>
> ++idx;
>
> > +             }
> > +
> > +             if (!idx) {
> > +                     printf("*** no RNG devices available ***\n");
>
> If idx is not initialized, depending on the random value of idx on the
> stack you get a printout or not, e.g.
>
> => rng list
> RNG #0 - riscv_zkr
> RNG #1 - virtio-rng#8
> *** no RNG devices available ***
>
> Do we need the message to be so noisy? How about
>
> log_err("No RNG device\n");
>
>
> > +                     return CMD_RET_FAILURE;
> > +             }
>
> We prefer having an empty line before return statements.
>
> Best regards
>
> Heinrich
>
> > +             return CMD_RET_SUCCESS;
> > +     }
> >
> >       switch (argc) {
> >       case 1:
> > @@ -57,6 +70,8 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> >   }
> >
> >   U_BOOT_LONGHELP(rng,
> > +     "[list]\n"
> > +     "  - list all the probe rng device\n"
> >       "[dev [n]]\n"
> >       "  - print n random bytes(max 64) read from dev\n");
> >
>

BR,
Weizhao