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From: Moshe Shemesh <moshe@nvidia.com>
Date: Thu, 17 Nov 2022 09:07:20 +0200
Subject: net/mlx5: Fix handling of entry refcount when command is not issued
 to FW
Patch-mainline: v6.1-rc7
Git-commit: aaf2e65cac7f2e1ae729c2fbc849091df9699f96
References: jsc#PED-1549

In case command interface is down, or the command is not allowed, driver
did not increment the entry refcount, but might have decrement as part
of forced completion handling.

Fix that by always increment and decrement the refcount to make it
symmetric for all flows.

Fixes: 50b2412b7e78 ("net/mlx5: Avoid possible free of command entry while timeout comp handler")
Signed-off-by: Eran Ben Elisha <eranbe@nvidia.com>
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reported-by: Jack Wang <jinpu.wang@ionos.com>
Tested-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -1005,6 +1005,7 @@ static void cmd_work_handler(struct work
 		cmd_ent_get(ent);
 	set_bit(MLX5_CMD_ENT_STATE_PENDING_COMP, &ent->state);
 
+	cmd_ent_get(ent); /* for the _real_ FW event on completion */
 	/* Skip sending command to fw if internal error */
 	if (mlx5_cmd_is_down(dev) || !opcode_allowed(&dev->cmd, ent->op)) {
 		ent->ret = -ENXIO;
@@ -1012,7 +1013,6 @@ static void cmd_work_handler(struct work
 		return;
 	}
 
-	cmd_ent_get(ent); /* for the _real_ FW event on completion */
 	/* ring doorbell after the descriptor is valid */
 	mlx5_core_dbg(dev, "writing 0x%x to command doorbell\n", 1 << ent->idx);
 	wmb();
@@ -1661,8 +1661,8 @@ static void mlx5_cmd_comp_handler(struct
 				cmd_ent_put(ent); /* timeout work was canceled */
 
 			if (!forced || /* Real FW completion */
-			    pci_channel_offline(dev->pdev) || /* FW is inaccessible */
-			    dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR)
+			     mlx5_cmd_is_down(dev) || /* No real FW completion is expected */
+			     !opcode_allowed(cmd, ent->op))
 				cmd_ent_put(ent);
 
 			ent->ts2 = ktime_get_ns();