net/mlx5: Stop polling for command response if interface goes down

Stop polling on firmware response to command in polling mode if the
command interface got down. This situation can occur, for example, if a
firmware fatal error is detected during polling.

This change halts the polling process when the command interface goes
down, preventing unnecessary waits.

Fixes: b898ce7 ("net/mlx5: cmdif, Avoid skipping reclaim pages if FW is not accessible")
Signed-off-by: Moshe Shemesh <[email protected]>
Reviewed-by: Shay Drori <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

Author: mosheshemesh2

drivers/net/ethernet/mellanox/mlx5/core/cmd.c

@@ -294,6 +294,10 @@ static void poll_timeout(struct mlx5_cmd_work_ent *ent)
 			return;
 		}
 		cond_resched();
+		if (mlx5_cmd_is_down(dev)) {
+			ent->ret = -ENXIO;
+			return;
+		}
 	} while (time_before(jiffies, poll_end));
 
 	ent->ret = -ETIMEDOUT;
@@ -1070,7 +1074,7 @@ static void cmd_work_handler(struct work_struct *work)
 		poll_timeout(ent);
 		/* make sure we read the descriptor after ownership is SW */
 		rmb();
-		mlx5_cmd_comp_handler(dev, 1ULL << ent->idx, (ent->ret == -ETIMEDOUT));
+		mlx5_cmd_comp_handler(dev, 1ULL << ent->idx, !!ent->ret);
 	}
 }