Re: [PATCH v2 9/9] hw/riscv: virt: Set the clock-frequency

[Bin Meng]

On Thu, Dec 16, 2021 at 12:55 PM Alistair Francis
<alistair.francis@opensource.wdc.com> wrote:
>
> From: Alistair Francis <alistair.francis@wdc.com>
>
> As per the device tree specification let's set the clock-frequency for
> the virt CPUs.
>
> QEMU doesn't really have an exact clock, so let's just 1000000 as it's a
> nice round number and matches the sifive_u CLINT_TIMEBASE_FREQ.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/472 (RISC-V virt)

I tend to think this issue is not valid, as the comment in the issue
says the value should reflect the running frequency.

Note the "clock-frequency" was once in the codes but was intentionally
removed before because it is not needed:

See commit 7ae05377b85f (" riscv: hw: Drop "clock-frequency" property
of cpu nodes")

> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  hw/riscv/virt.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 3af074148e..41a85cfc60 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -202,6 +202,7 @@ static void create_fdt_socket_cpus(RISCVVirtState *s, int 
> socket,
>          qemu_fdt_setprop_cell(mc->fdt, cpu_name, "reg",
>              s->soc[socket].hartid_base + cpu);
>          qemu_fdt_setprop_string(mc->fdt, cpu_name, "device_type", "cpu");
> +        qemu_fdt_setprop_cell(mc->fdt, cpu_name, "clock-frequency", 1000000);
>          riscv_socket_fdt_write_id(mc, mc->fdt, cpu_name, socket);
>          qemu_fdt_setprop_cell(mc->fdt, cpu_name, "phandle", cpu_phandle);

Regards,
Bin