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

[Przemyslaw Korba <przemyslaw.korba@intel.com>]

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>
---
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)
 {
 	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
-- 
2.43.0