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

[Tony Nguyen <anthony.l.nguyen@intel.com>]

On 3/10/2026 4:17 AM, Loktionov, Aleksandr wrote:
> 
> 
>> -----Original Message-----
>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
>> Of Przemyslaw Korba
>> Sent: Tuesday, March 10, 2026 12:07 PM
>> To: intel-wired-lan@lists.osuosl.org
>> Cc: netdev@vger.kernel.org; Nguyen, Anthony L
>> <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw
>> <przemyslaw.kitszel@intel.com>; Korba, Przemyslaw
>> <przemyslaw.korba@intel.com>
>> Subject: [Intel-wired-lan] [PATCH iwl-net] ice: fix posted write
>> support for sideband queue operations
>>
>> 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:
>>
>> 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>
>> ---
>>   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..df9e5422b981 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)  {
>>   	struct ice_sbq_cmd_desc desc = {0};
>>   	struct ice_sbq_msg_req msg = {0};
>> +	struct ice_sq_cd cd = {0};

Please init without the 0 i.e. {}

>>   	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.postpone = 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..5fb3a8441beb 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->postpone)
>> +		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..7c98d3a0314e 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 postpone : 1;
> I'd recommend to rename postpone -> posted to match terminology /* posted write */.

I think the name is a bit misleading. To not wait, we need to set 
'postpone'? I would think postpone means we want to wait. If we want to 
represent functionality, maybe something like 'skip_wait' or if we 
wanted to match the documentation, perhaps 'posted' as Alex suggested.

Thanks,
Tony

> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> 
>>   };
>>
>>   /* rq event information */
>>
>> base-commit: acd2abc52dea91c3bc3d1b6dd8a92b9631d48bbf
>> --
>> 2.43.0
>