Re: [PATCH 5/5] ice: quiesce PTP periodic work before system suspend

[Jacob Keller <jacob.e.keller@intel.com>]

On 10/19/2026 3:51 AM, Aaron Ma wrote:
> ice_suspend() stops the main service task but leaves PTP work active.
> The PTP kworker is not freezable, so it can continue issuing MMIO
> accesses after the PCI function has entered D3hot. Both the periodic
> work updating the cached PHC time and the E822 offset calibration work,
> which reschedules itself while calibration is pending, are affected.
> 
> Synchronously cancel both works when PTP is ready, after disabling the
> VSIs and before shutting down the control queues.
> 
> Fixes: 77a781155a65 ("ice: enable receive hardware timestamping")
> Fixes: a69f1cb62aec ("ice: exit bypass mode once hardware finishes timestamp calibration")
> Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
> index ddebb28b2454f..3962910759067 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -5450,6 +5450,12 @@ static void ice_prepare_for_shutdown(struct ice_pf *pf)
>  	/* disable the VSIs and their queues that are not already DOWN */
>  	ice_pf_dis_all_vsi(pf, false);
>  
> +	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags) &&
> +	    pf->ptp.state == ICE_PTP_READY) {
> +		kthread_cancel_delayed_work_sync(&pf->ptp.work);
> +		kthread_cancel_delayed_work_sync(&pf->ptp.port.ov_work);
> +	}
> +
>  	ice_for_each_vsi(pf, v)
>  		if (pf->vsi[v])
>  			pf->vsi[v]->vsi_num = 0;

I don't think kthread has the same API as workers to fully disable
re-queueing, but at least the periodic work is only requeueud within its
own run or by rebuild flows. ov_work I am not fully sure about, I guess
it depends on if this can race with another thread that would
re-schedule. I believe the PTP teardown also cancel the tasks but may
happen later than needed? But maybe we lack a PTP flow for
prepare_for_shutdown. Hmm.

This is at least better than what we do now so:

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>