Re: [PATCH] target/loongarch: Set timer tick value even if disabled

Hi Bibo Mao :
> If constant timer is enabled, its tick value is remained value from
> the next expired time. However if timer is not enabled, its value
> should be CONSTANT_TIMER_TICK_MASK or zero.
>
> Signed-off-by: Bibo Mao <[email protected]>
> ---
>   target/loongarch/tcg/constant_timer.c | 17 +++++++++++++----
>   1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/target/loongarch/tcg/constant_timer.c b/target/loongarch/tcg/constant_timer.c
> index f56e76d482..b91ad1de69 100644
> --- a/target/loongarch/tcg/constant_timer.c
> +++ b/target/loongarch/tcg/constant_timer.c
> @@ -22,12 +22,18 @@ uint64_t cpu_loongarch_get_constant_timer_counter(LoongArchCPU *cpu)
>   
>   uint64_t cpu_loongarch_get_constant_timer_ticks(LoongArchCPU *cpu)
>   {
> +    CPULoongArchState *env = &cpu->env;
> +    CPUSysState *sys = env_sys(env);
>       uint64_t now, expire;
>   
> -    now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> -    expire = timer_expire_time_ns(&cpu->timer);
> +    if ((sys->CSR_TCFG & CONSTANT_TIMER_ENABLE) &&
> +        (sys->CSR_TVAL < sys->CSR_TCFG)) {
> +        now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +        expire = timer_expire_time_ns(&cpu->timer);
> +        sys->CSR_TVAL = (expire - now) / TIMER_PERIOD;
> +    }
>   
> -    return (expire - now) / TIMER_PERIOD;
> +    return sys->CSR_TVAL;
>   }
>   
>   void cpu_loongarch_store_constant_timer_config(LoongArchCPU *cpu,
> @@ -42,8 +48,10 @@ void cpu_loongarch_store_constant_timer_config(LoongArchCPU *cpu,
>           now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
>           next = now + (value & CONSTANT_TIMER_TICK_MASK) * TIMER_PERIOD;
>           timer_mod(&cpu->timer, next);
> +        sys->CSR_TVAL = sys->CSR_TCFG & CONSTANT_TIMER_TICK_MASK;
>       } else {
>           timer_del(&cpu->timer);
> +        sys->CSR_TVAL = 0;
>       }
>   }
>   
> @@ -58,8 +66,9 @@ void loongarch_constant_timer_cb(void *opaque)
>           now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
>           next = now + (sys->CSR_TCFG & CONSTANT_TIMER_TICK_MASK) * TIMER_PERIOD;
>           timer_mod(&cpu->timer, next);
> +        sys->CSR_TVAL = sys->CSR_TCFG & CONSTANT_TIMER_TICK_MASK;
>       } else {
> -        sys->CSR_TCFG = FIELD_DP64(sys->CSR_TCFG, CSR_TCFG, EN, 0);
> +        sys->CSR_TVAL = CONSTANT_TIMER_TICK_MASK;
>       }
>   
>       loongarch_cpu_set_irq(opaque, IRQ_TIMER, 1);
Reviewed-by: Xianglai Li <[email protected]>
> base-commit: a759542a2c62f0fd3b65f5a66ad9868201014669