Re: [PATCH] iothread: Simplify expression in qemu_in_iothread()

[Peter Maydell]

On Thu, 8 Feb 2024 at 14:22, Kevin Wolf <kwolf@redhat.com> wrote:
>
> Am 08.02.2024 um 11:48 hat Philippe Mathieu-Daudé geschrieben:
> > BTW using the same pattern:
> >
> > -- >8 --
> > diff --git a/hw/nvram/xlnx-zynqmp-efuse.c b/hw/nvram/xlnx-zynqmp-efuse.c
> > index ec98456e5d..d074762a25 100644
> > --- a/hw/nvram/xlnx-zynqmp-efuse.c
> > +++ b/hw/nvram/xlnx-zynqmp-efuse.c
> > @@ -582,7 +582,7 @@ static uint64_t
> > zynqmp_efuse_cache_load_prew(RegisterInfo *reg,
> >
> >  static uint64_t zynqmp_efuse_wr_lock_prew(RegisterInfo *reg, uint64_t val)
> >  {
> > -    return val == 0xDF0D ? 0 : 1;
> > +    return val != 0xDF0D;
> >  }
>
> Maybe. I would have to know that device to tell if this is really meant
> as boolean. Or maybe it should be written 0x0 and 0x1 to signify that
> it's a register value or something.

This is a RegisterAccessinfo pre_write hook. The docs say:
 * @pre_write: Pre write callback. Passed the value that's to be written,
 * immediately before the actual write. The returned value is what is written,
 * giving the handler a chance to modify the written value.

So it is indeed returning a register value, not a boolean flag
masquerading as a uint64_t.

> > diff --git a/tests/tcg/aarch64/sysregs.c b/tests/tcg/aarch64/sysregs.c
> > index 301e61d0dd..bdd73bd181 100644
> > --- a/tests/tcg/aarch64/sysregs.c
> > +++ b/tests/tcg/aarch64/sysregs.c
> > @@ -183,5 +183,5 @@ int main(void)
> >          return 1;
> >      }
> >
> > -    return should_fail_count == 6 ? 0 : 1;
> > +    return should_fail_count != 6;
> >  }
>
> This one isn't unclear to me, though. This is EXIT_SUCCESS and
> EXIT_FAILURE, just open-coded. I think making your change would make it
> only more confusing.

I agree on this one.

-- PMM