[PATCH iwl-net 1/2] ice: reintroduce retry mechanism for indirect AQ

[Dawid Osuchowski <dawid.osuchowski@linux.intel.com>]

From: Jakub Staniszewski <jakub.staniszewski@linux.intel.com>

Add retry mechanism for indirect Admin Queue (AQ) commands. To do so we
need to keep the command buffer.

This technically reverts commit 43a630e37e25
("ice: remove unused buffer copy code in ice_sq_send_cmd_retry()"),
but combines it with a fix in the logic by using a kmemdup() call,
making it more robust and less likely to break in the future due to
programmer error.

Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 3056df93f7a8 ("ice: Re-send some AQ commands, as result of EBUSY AQ error")
Signed-off-by: Jakub Staniszewski <jakub.staniszewski@linux.intel.com>
Co-developed-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com>
Signed-off-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
---
Ccing Michal, given they are the author of the "reverted" commit.

 drivers/net/ethernet/intel/ice/ice_common.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
index a400bf4f239a..aab00c44e9b2 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.c
+++ b/drivers/net/ethernet/intel/ice/ice_common.c
@@ -1879,34 +1879,40 @@ ice_sq_send_cmd_retry(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 {
 	struct libie_aq_desc desc_cpy;
 	bool is_cmd_for_retry;
+	u8 *buf_cpy = NULL;
 	u8 idx = 0;
 	u16 opcode;
 	int status;
 
 	opcode = le16_to_cpu(desc->opcode);
 	is_cmd_for_retry = ice_should_retry_sq_send_cmd(opcode);
 	memset(&desc_cpy, 0, sizeof(desc_cpy));
 
 	if (is_cmd_for_retry) {
-		/* All retryable cmds are direct, without buf. */
-		WARN_ON(buf);
+		if (buf) {
+			buf_cpy = kmemdup(buf, buf_size, GFP_KERNEL);
+			if (!buf_cpy)
+				return -ENOMEM;
+		}
 
 		memcpy(&desc_cpy, desc, sizeof(desc_cpy));
 	}
 
 	do {
 		status = ice_sq_send_cmd(hw, cq, desc, buf, buf_size, cd);
 
 		if (!is_cmd_for_retry || !status ||
 		    hw->adminq.sq_last_status != LIBIE_AQ_RC_EBUSY)
 			break;
 
+		if (buf_cpy)
+			memcpy(buf, buf_cpy, buf_size);
 		memcpy(desc, &desc_cpy, sizeof(desc_cpy));
-
 		msleep(ICE_SQ_SEND_DELAY_TIME_MS);
 
 	} while (++idx < ICE_SQ_SEND_MAX_EXECUTE);
 
+	kfree(buf_cpy);
 	return status;
 }
 
-- 
2.51.0