Re: [PATCH 2/4] target/mips: Don't use clock_get_ns() in clock period calculation

[Luc Michel]

On 12/8/20 7:15 PM, Peter Maydell wrote:
> Currently the MIPS code uses the old clock_get_ns() API to
> calculate a time length in nanoseconds:
>   cpu->cp0_count_rate * clock_get_ns(MIPS_CPU(cpu)->clock)
>
> This relies on the clock having a period which is an exact number
> of nanoseconds.
>
> Switch to the new clock_ticks_to_ns() function, which does the
> multiplication internally at a higher precision.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Luc Michel <luc@lmichel.fr>

> ---
>   target/mips/cpu.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/mips/cpu.c b/target/mips/cpu.c
> index 76d50b00b42..de15ec6068a 100644
> --- a/target/mips/cpu.c
> +++ b/target/mips/cpu.c
> @@ -147,8 +147,8 @@ static void mips_cp0_period_set(MIPSCPU *cpu)
>   {
>       CPUMIPSState *env = &cpu->env;
>   
> -    env->cp0_count_ns = cpu->cp0_count_rate
> -                        * clock_get_ns(MIPS_CPU(cpu)->clock);
> +    env->cp0_count_ns = clock_ticks_to_ns(MIPS_CPU(cpu)->clock,
> +                                          cpu->cp0_count_rate);
>       assert(env->cp0_count_ns);
>   }
>