On Fri, 9 Apr 2021 at 07:24, Philippe Mathieu-Daudé <f4...@amsat.org> wrote:
>
> While the documentation mentions:
>
> Note that if you are creating a clock with a fixed period which
> will never change (for example the main clock source of a board),
> then you'll have nothing else to do. This value will be propagated
> to other clocks when connecting the clocks together and devices
> will fetch the right value during the first reset.
>
> the clocks created in machine_init() aren't propagating their value
> because they are never reset (not part of the reset tree, such
> TYPE_DEVICE).
>
> Register a generic reset handler to have them properly reset.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> ---
> hw/core/machine.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index e8bdcd10854..2817fe6a567 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -1234,6 +1234,13 @@ void machine_run_board_init(MachineState *machine)
> phase_advance(PHASE_MACHINE_INITIALIZED);
> }
>
> +static void constant_clock_reset(void *opaque)
> +{
> + Clock *clk = opaque;
> +
> + clock_propagate(clk);
> +}
> +
> Clock *machine_create_constant_clock(MachineState *machine,
> const char *name, unsigned freq_hz)
> {
> @@ -1241,6 +1248,7 @@ Clock *machine_create_constant_clock(MachineState
> *machine,
>
> clk = clock_new(OBJECT(machine), name);
> clock_set_hz(clk, freq_hz);
> + qemu_register_reset(constant_clock_reset, clk);
You mention this in the cover letter, but I agree that this
isn't really very nice. The machine's reset method ought to
reset the clocks (either explicitly or maybe some day implicitly).
thanks
-- PMM
