net: ena: allow automatic fallback to polling mode

Enable fallback to polling mode for Admin queue
when identified a command response arrival
without an accompanying MSI-X interrupt

Signed-off-by: Igor Chauskin <igorch@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 9 deletions

diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
index 139b31549b15..5e2abdda73d1 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -762,16 +762,26 @@ static int ena_com_wait_and_process_admin_cq_interrupts(struct ena_comp_ctx *com
 		admin_queue->stats.no_completion++;
 		spin_unlock_irqrestore(&admin_queue->q_lock, flags);
 
-		if (comp_ctx->status == ENA_CMD_COMPLETED)
-			pr_err("The ena device have completion but the driver didn't receive any MSI-X interrupt (cmd %d)\n",
-			       comp_ctx->cmd_opcode);
-		else
-			pr_err("The ena device doesn't send any completion for the admin cmd %d status %d\n",
+		if (comp_ctx->status == ENA_CMD_COMPLETED) {
+			pr_err("The ena device sent a completion but the driver didn't receive a MSI-X interrupt (cmd %d), autopolling mode is %s\n",
+			       comp_ctx->cmd_opcode,
+			       admin_queue->auto_polling ? "ON" : "OFF");
+			/* Check if fallback to polling is enabled */
+			if (admin_queue->auto_polling)
+				admin_queue->polling = true;
+		} else {
+			pr_err("The ena device doesn't send a completion for the admin cmd %d status %d\n",
 			       comp_ctx->cmd_opcode, comp_ctx->status);
-
-		admin_queue->running_state = false;
-		ret = -ETIME;
-		goto err;
+		}
+		/* Check if shifted to polling mode.
+		 * This will happen if there is a completion without an interrupt
+		 * and autopolling mode is enabled. Continuing normal execution in such case
+		 */
+		if (!admin_queue->polling) {
+			admin_queue->running_state = false;
+			ret = -ETIME;
+			goto err;
+		}
 	}
 
 	ret = ena_com_comp_status_to_errno(comp_ctx->comp_status);
@@ -1650,6 +1660,12 @@ void ena_com_set_admin_polling_mode(struct ena_com_dev *ena_dev, bool polling)
 	ena_dev->admin_queue.polling = polling;
 }
 
+void ena_com_set_admin_auto_polling_mode(struct ena_com_dev *ena_dev,
+					 bool polling)
+{
+	ena_dev->admin_queue.auto_polling = polling;
+}
+
 int ena_com_mmio_reg_read_request_init(struct ena_com_dev *ena_dev)
 {
 	struct ena_com_mmio_read *mmio_read = &ena_dev->mmio_read;