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

Atish Patra
2019-01-18T02:10:36Z

On 1/8/19 3:57 AM, Anup Patel wrote:
> 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@wdc.com> 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@wdc.com>
>> ---
>> 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@brainfault.org>
>

Thanks for the review. I will fix the empty line issues and subject line.

> Regards,
> Anup
>