Re: [Intel-wired-lan] [PATCH iwl-net v2] ice: fix posted write support for sideband queue operations

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

On 3/19/2026 4:13 AM, Przemyslaw Korba wrote:
> On E830, PTP time adjustment commands sent via
> SBQ don't generate completion responses, causing the driver to
> timeout waiting and return -EIO, when trying:
> 
 Hm. Is this really for E830? I didn't realize that device actually
sends SBQ commands for PTP?

According to ice_ptp_adj_clock for E830, it says "E830 sync PHYs
automatically after setting GLTSYN_SHADJ".

Did you mean E825-C here? Can you confirm the device type affected? Or
am I missing something?

> phc_ctl eth8 get adj 2 get
> dmesg: ice 0000:1a:00.0: PTP failed to adjust time, err -5
> 
> Add support for posted mode not to wait for completion response.
> 
> Fixes: 8f5ee3c477a8 ("ice: add support for sideband messages")
> Signed-off-by: Przemyslaw Korba <przemyslaw.korba@intel.com>
> ---
> v2:
> - change "postpone" to "posted"
> - init struct with {} instead of {0}
> v1:
> https://lore.kernel.org/intel-wired-lan/20260310110700.345904-1-przemyslaw.korba@intel.com/
> 
>  drivers/net/ethernet/intel/ice/ice_common.c   | 7 ++++++-
>  drivers/net/ethernet/intel/ice/ice_controlq.c | 4 ++++
>  drivers/net/ethernet/intel/ice/ice_controlq.h | 1 +
>  3 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
> index 8866902efb91..c89c6ca1281b 100644
> --- a/drivers/net/ethernet/intel/ice/ice_common.c
> +++ b/drivers/net/ethernet/intel/ice/ice_common.c
> @@ -1765,6 +1765,7 @@ int ice_sbq_rw_reg(struct ice_hw *hw, struct ice_sbq_msg_input *in, u16 flags)
>  {

This affects the ice_sbq_rw_reg function which is used by several
variants including the E822 devices, E825-C with ETH56G, and even E810
devices.

Do all these devices not provide completion? Or do we simply not care
about waiting?

I don't see a single call to ice_sbq_rw_reg for E830, so I suspect this
is correct but for a different device, and the commit message is just a
typo?

>  	struct ice_sbq_cmd_desc desc = {0};
>  	struct ice_sbq_msg_req msg = {0};
> +	struct ice_sq_cd cd = {};
>  	u16 msg_len;
>  	int status;
>  
> @@ -1785,10 +1786,14 @@ int ice_sbq_rw_reg(struct ice_hw *hw, struct ice_sbq_msg_input *in, u16 flags)
>  		 */
>  		msg_len -= sizeof(msg.data);
>  
> +	if (in->opcode == ice_sbq_msg_wr)
> +		cd.posted = 1;
> +
>  	desc.flags = cpu_to_le16(flags);
>  	desc.opcode = cpu_to_le16(ice_sbq_opc_neigh_dev_req);
>  	desc.param0.cmd_len = cpu_to_le16(msg_len);
> -	status = ice_sbq_send_cmd(hw, &desc, &msg, msg_len, NULL);
> +	status = ice_sbq_send_cmd(hw, &desc, &msg, msg_len, &cd);
> +
>  	if (!status && !in->opcode)
>  		in->data = le32_to_cpu
>  			(((struct ice_sbq_msg_cmpl *)&msg)->data);
> diff --git a/drivers/net/ethernet/intel/ice/ice_controlq.c b/drivers/net/ethernet/intel/ice/ice_controlq.c
> index dcb837cadd18..a6008dc77fa4 100644
> --- a/drivers/net/ethernet/intel/ice/ice_controlq.c
> +++ b/drivers/net/ethernet/intel/ice/ice_controlq.c
> @@ -1086,6 +1086,10 @@ ice_sq_send_cmd(struct ice_hw *hw, struct ice_ctl_q_info *cq,
>  	wr32(hw, cq->sq.tail, cq->sq.next_to_use);
>  	ice_flush(hw);
>  
> +	/* If the message is posted, don't wait for completion. */
> +	if (cd && cd->posted)
> +		goto sq_send_command_error;
> +
>  	/* Wait for the command to complete. If it finishes within the
>  	 * timeout, copy the descriptor back to temp.
>  	 */
> diff --git a/drivers/net/ethernet/intel/ice/ice_controlq.h b/drivers/net/ethernet/intel/ice/ice_controlq.h
> index 788040dd662e..c50d6fcbacba 100644
> --- a/drivers/net/ethernet/intel/ice/ice_controlq.h
> +++ b/drivers/net/ethernet/intel/ice/ice_controlq.h
> @@ -77,6 +77,7 @@ struct ice_ctl_q_ring {
>  /* sq transaction details */
>  struct ice_sq_cd {
>  	struct libie_aq_desc *wb_desc;
> +	u8 posted : 1;
>  };
>  
>  /* rq event information */
> 
> base-commit: acd2abc52dea91c3bc3d1b6dd8a92b9631d48bbf