Re: [PATCH v2 6/8] RISC-V: Add required checks during clock source init

[Anup Patel]

Few nit changes..

Prefer, "clocksource/drivers/riscv:" prefix instead of "RISC-V:" for
this patch.

On Tue, Jan 8, 2019 at 3:08 PM Atish Patra <atish.patra@xxxxxxx> wrote:
>
> Currently, clocksource registration happens for an invalid cpu
> for non-smp kernels. This lead to kernel panic as cpu hotplug
> registration will fail for those cpus. Moreover,
> riscv_hartid_to_cpuid can return errors now.
>
> Do not proceed if hartid or cpuid is invalid. Take this opprtunity
> to print appropriate error strings for different failure cases.
>
> Signed-off-by: Atish Patra <atish.patra@xxxxxxx>
> ---
>  drivers/clocksource/timer-riscv.c | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
> index 43189220..d9b914e9 100644
> --- a/drivers/clocksource/timer-riscv.c
> +++ b/drivers/clocksource/timer-riscv.c
> @@ -95,14 +95,31 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>         struct clocksource *cs;
>
>         hartid = riscv_of_processor_hartid(n);
> +       if (hartid < 0) {
> +               pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
> +                       n, hartid);
> +               return hartid;
> +       }

Add empty line here.

>         cpuid = riscv_hartid_to_cpuid(hartid);
>

Remove empty line here

> +       if (cpuid < 0) {
> +               pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
> +               return cpuid;
> +       }
> +
>         if (cpuid != smp_processor_id())
>                 return 0;
>
> +       pr_err("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
> +              __func__, cpuid, hartid);
>         cs = per_cpu_ptr(&riscv_clocksource, cpuid);
> -       clocksource_register_hz(cs, riscv_timebase);
> +       error = clocksource_register_hz(cs, riscv_timebase);
>

Remove empty line here.

> +       if (error) {
> +               pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
> +                      error, cpuid);
> +               return error;
> +       }

Add empty line here.

>         sched_clock_register(riscv_sched_clock,
>                         BITS_PER_LONG, riscv_timebase);
>
> @@ -110,8 +127,8 @@ static int __init riscv_timer_init_dt(struct device_node *n)
>                          "clockevents/riscv/timer:starting",
>                          riscv_timer_starting_cpu, riscv_timer_dying_cpu);
>         if (error)
> -               pr_err("RISCV timer register failed [%d] for cpu = [%d]\n",
> -                      error, cpuid);
> +               pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
> +                      error);
>         return error;
>  }
>
> --
> 2.7.4
>

Apart from above, looks good to me.

Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

Regards,
Anup