Re: [PATCH iwl-net v1] i40e: fix races in PTP external timestamp work handling

[luoxuanqiang <xuanqiang.luo@linux.dev>]

在 2026/8/5 05:33, Vadim Fedorenko 写道:
> On 24/07/2026 10:34, xuanqiang.luo@linux.dev wrote:
>>
>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c 
>> b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
>> index ff62b5f2c8150..fd51ab8c10c20 100644
>> --- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
>> +++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
>> @@ -169,6 +169,17 @@ static void i40e_ptp_extts0_work(struct 
>> work_struct *work)
>>       ptp_clock_event(pf->ptp_clock, &event);
>>   }
>>   +/**
>> + * i40e_ptp_init_work - Initialize PTP work for a PF
>> + * @pf: Board private structure
>> + *
>> + * Initialize work which must remain valid for the lifetime of the PF.
>> + */
>> +void i40e_ptp_init_work(struct i40e_pf *pf)
>> +{
>> +    INIT_WORK(&pf->ptp_extts0_work, i40e_ptp_extts0_work);
>> +}
>> +
>
> why do you need extra function for a single line of code? why cannot 
> you put it into i40e_ptp_init?
>
>
Thanks for pointing this out.

i40e_ptp_init() is also called from the reset/rebuild path:

   i40e_service_task()
     -> i40e_reset_subtask()
       -> i40e_reset_and_rebuild()
         -> i40e_rebuild()
           -> i40e_setup_pf_switch()
             -> i40e_ptp_init()

Putting INIT_WORK() there would reinitialize the work item during reset or
recovery. If the work is pending or running, this races with the workqueue,
resets its bookkeeping, and breaks the workqueue's non-reentrance
guarantee.

The work item is therefore initialized once per PF from i40e_sw_init().
The helper also keeps the work callback private to i40e_ptp.c.