Re: [PATCH net-next 09/10] ice: dpll: update locking comments

[Petr Oros <poros@redhat.com>]

On 11/6/26 1:10 PM, Ivan Vecera wrote:
> Callbacks run under the DPLL core domain locks instead of dpll_lock. Note
> that callbacks of pins of an external DPLL run under the domain of that
> DPLL, so only pf->dplls.lock serializes them with the rest of the driver.
> 
> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
> ---
>   drivers/net/ethernet/intel/ice/ice_dpll.c | 4 ++--
>   drivers/net/ethernet/intel/ice/ice_dpll.h | 3 +++
>   2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c b/drivers/net/ethernet/intel/ice/ice_dpll.c
> index d6302409a2dacf..07cbd4cf0160ca 100644
> --- a/drivers/net/ethernet/intel/ice/ice_dpll.c
> +++ b/drivers/net/ethernet/intel/ice/ice_dpll.c
> @@ -1178,8 +1178,8 @@ ice_dpll_input_state_get(const struct dpll_pin *pin, void *pin_priv,
>    * peer via dpll netlink learn about the update.
>    *
>    * Context: Called from dpll_pin_ops callbacks after pf->dplls.lock is
> - *          released.  Uses __dpll_pin_change_ntf() because dpll_lock is
> - *          still held by the dpll netlink layer.
> + *          released.  Uses __dpll_pin_change_ntf() because the domain lock
> + *          is still held by the dpll core.
>    */
>   static void ice_dpll_sw_pin_notify_peer(struct ice_dplls *d,
>   					struct ice_dpll_pin *changed)
> diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.h b/drivers/net/ethernet/intel/ice/ice_dpll.h
> index 4ba76e2e2e0b01..39e041a30090d0 100644
> --- a/drivers/net/ethernet/intel/ice/ice_dpll.h
> +++ b/drivers/net/ethernet/intel/ice/ice_dpll.h
> @@ -165,6 +165,9 @@ struct ice_dpll {
>    *     tx_refclks usage map), acquire pf->dplls.lock first, then
>    *     ctrl_pf->dplls.lock. Skip the second acquire when pf == ctrl_pf
>    *     to avoid recursive locking.
> + *   - Callbacks of the SYNCE and TIME_REF pins of an external DPLL run under
> + *     the DPLL core domain lock of that DPLL, not of the TXC and TSPLL DPLLs,
> + *     so only @lock serializes them with the callbacks of these DPLLs.
>    *   - @txclk_notify_rwsem is held for read across
>    *     ice_txclk_update_and_notify(), including the out-of-lock
>    *     dpll_*_change_ntf() calls. ice_dpll_deinit() takes the write side
Reviewed-by: Petr Oros <poros@redhat.com>