net: ethernet: ti: am65-cpsw: ensure proper channel cleanup in error path

We are missing netif_napi_del() and am65_cpsw_nuss_free_tx/rx_chns()
in error path when am65_cpsw_nuss_init_tx/rx_chns() is used anywhere
other than at probe(). i.e. am65_cpsw_nuss_update_tx_rx_chns and
am65_cpsw_nuss_resume()

As reported, in am65_cpsw_nuss_update_tx_rx_chns(),
if am65_cpsw_nuss_init_tx_chns() partially fails then
devm_add_action(dev, am65_cpsw_nuss_free_tx_chns,..) is added
but the cleanup via am65_cpsw_nuss_free_tx_chns() will not run.

Same issue exists for am65_cpsw_nuss_init_tx/rx_chns() failures
in am65_cpsw_nuss_resume() as well.

This would otherwise require more instances of devm_add/remove_action
and is clearly more of a distraction than any benefit.

So, drop devm_add/remove_action for am65_cpsw_nuss_free_tx/rx_chns()
and call am65_cpsw_nuss_free_tx/rx_chns() and netif_napi_del()
where required.

Reported-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Closes: https://lore.kernel.org/all/m4rhkzcr7dlylxr54udyt6lal5s2q4krrvmyay6gzgzhcu4q2c@r34snfumzqxy/
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Link: https://patch.msgid.link/20250117-am65-cpsw-streamline-v2-1-91a29c97e569@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: rogerq

drivers/net/ethernet/ti/am65-cpsw-nuss.c

@@ -2252,8 +2252,6 @@ static void am65_cpsw_nuss_remove_tx_chns(struct am65_cpsw_common *common)
 	struct device *dev = common->dev;
 	int i;
 
-	devm_remove_action(dev, am65_cpsw_nuss_free_tx_chns, common);
-
 	common->tx_ch_rate_msk = 0;
 	for (i = 0; i < common->tx_ch_num; i++) {
 		struct am65_cpsw_tx_chn *tx_chn = &common->tx_chns[i];
@@ -2275,8 +2273,6 @@ static int am65_cpsw_nuss_ndev_add_tx_napi(struct am65_cpsw_common *common)
 	for (i = 0; i < common->tx_ch_num; i++) {
 		struct am65_cpsw_tx_chn *tx_chn = &common->tx_chns[i];
 
-		netif_napi_add_tx(common->dma_ndev, &tx_chn->napi_tx,
-				  am65_cpsw_nuss_tx_poll);
 		hrtimer_init(&tx_chn->tx_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
 		tx_chn->tx_hrtimer.function = &am65_cpsw_nuss_tx_timer_callback;
 
@@ -2289,9 +2285,21 @@ static int am65_cpsw_nuss_ndev_add_tx_napi(struct am65_cpsw_common *common)
 				tx_chn->id, tx_chn->irq, ret);
 			goto err;
 		}
+
+		netif_napi_add_tx(common->dma_ndev, &tx_chn->napi_tx,
+				  am65_cpsw_nuss_tx_poll);
 	}
 
+	return 0;
+
 err:
+	for (--i ; i >= 0 ; i--) {
+		struct am65_cpsw_tx_chn *tx_chn = &common->tx_chns[i];
+
+		netif_napi_del(&tx_chn->napi_tx);
+		devm_free_irq(dev, tx_chn->irq, tx_chn);
+	}
+
 	return ret;
 }
 
@@ -2372,12 +2380,10 @@ static int am65_cpsw_nuss_init_tx_chns(struct am65_cpsw_common *common)
 		goto err;
 	}
 
+	return 0;
+
 err:
-	i = devm_add_action(dev, am65_cpsw_nuss_free_tx_chns, common);
-	if (i) {
-		dev_err(dev, "Failed to add free_tx_chns action %d\n", i);
-		return i;
-	}
+	am65_cpsw_nuss_free_tx_chns(common);
 
 	return ret;
 }
@@ -2405,7 +2411,6 @@ static void am65_cpsw_nuss_remove_rx_chns(struct am65_cpsw_common *common)
 
 	rx_chn = &common->rx_chns;
 	flows = rx_chn->flows;
-	devm_remove_action(dev, am65_cpsw_nuss_free_rx_chns, common);
 
 	for (i = 0; i < common->rx_ch_num_flows; i++) {
 		if (!(flows[i].irq < 0))
@@ -2504,7 +2509,7 @@ static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common)
 						i, &rx_flow_cfg);
 		if (ret) {
 			dev_err(dev, "Failed to init rx flow%d %d\n", i, ret);
-			goto err;
+			goto err_flow;
 		}
 		if (!i)
 			fdqring_id =
@@ -2516,14 +2521,12 @@ static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common)
 			dev_err(dev, "Failed to get rx dma irq %d\n",
 				flow->irq);
 			ret = flow->irq;
-			goto err;
+			goto err_flow;
 		}
 
 		snprintf(flow->name,
 			 sizeof(flow->name), "%s-rx%d",
 			 dev_name(dev), i);
-		netif_napi_add(common->dma_ndev, &flow->napi_rx,
-			       am65_cpsw_nuss_rx_poll);
 		hrtimer_init(&flow->rx_hrtimer, CLOCK_MONOTONIC,
 			     HRTIMER_MODE_REL_PINNED);
 		flow->rx_hrtimer.function = &am65_cpsw_nuss_rx_timer_callback;
@@ -2536,20 +2539,28 @@ static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common)
 			dev_err(dev, "failure requesting rx %d irq %u, %d\n",
 				i, flow->irq, ret);
 			flow->irq = -EINVAL;
-			goto err;
+			goto err_flow;
 		}
+
+		netif_napi_add(common->dma_ndev, &flow->napi_rx,
+			       am65_cpsw_nuss_rx_poll);
 	}
 
 	/* setup classifier to route priorities to flows */
 	cpsw_ale_classifier_setup_default(common->ale, common->rx_ch_num_flows);
 
-err:
-	i = devm_add_action(dev, am65_cpsw_nuss_free_rx_chns, common);
-	if (i) {
-		dev_err(dev, "Failed to add free_rx_chns action %d\n", i);
-		return i;
+	return 0;
+
+err_flow:
+	for (--i; i >= 0 ; i--) {
+		flow = &rx_chn->flows[i];
+		netif_napi_del(&flow->napi_rx);
+		devm_free_irq(dev, flow->irq, flow);
 	}
 
+err:
+	am65_cpsw_nuss_free_rx_chns(common);
+
 	return ret;
 }
 
@@ -3354,7 +3365,7 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
 		return ret;
 	ret = am65_cpsw_nuss_init_rx_chns(common);
 	if (ret)
-		return ret;
+		goto err_remove_tx;
 
 	/* The DMA Channels are not guaranteed to be in a clean state.
 	 * Reset and disable them to ensure that they are back to the
@@ -3375,7 +3386,7 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
 
 	ret = am65_cpsw_nuss_register_devlink(common);
 	if (ret)
-		return ret;
+		goto err_remove_rx;
 
 	for (i = 0; i < common->port_num; i++) {
 		port = &common->ports[i];
@@ -3406,6 +3417,10 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
 err_cleanup_ndev:
 	am65_cpsw_nuss_cleanup_ndev(common);
 	am65_cpsw_unregister_devlink(common);
+err_remove_rx:
+	am65_cpsw_nuss_remove_rx_chns(common);
+err_remove_tx:
+	am65_cpsw_nuss_remove_tx_chns(common);
 
 	return ret;
 }
@@ -3425,6 +3440,8 @@ int am65_cpsw_nuss_update_tx_rx_chns(struct am65_cpsw_common *common,
 		return ret;
 
 	ret = am65_cpsw_nuss_init_rx_chns(common);
+	if (ret)
+		am65_cpsw_nuss_remove_tx_chns(common);
 
 	return ret;
 }
@@ -3683,6 +3700,8 @@ static void am65_cpsw_nuss_remove(struct platform_device *pdev)
 	 */
 	am65_cpsw_nuss_cleanup_ndev(common);
 	am65_cpsw_unregister_devlink(common);
+	am65_cpsw_nuss_remove_rx_chns(common);
+	am65_cpsw_nuss_remove_tx_chns(common);
 	am65_cpsw_nuss_phylink_cleanup(common);
 	am65_cpts_release(common->cpts);
 	am65_cpsw_disable_serdes_phy(common);
@@ -3744,8 +3763,10 @@ static int am65_cpsw_nuss_resume(struct device *dev)
 	if (ret)
 		return ret;
 	ret = am65_cpsw_nuss_init_rx_chns(common);
-	if (ret)
+	if (ret) {
+		am65_cpsw_nuss_remove_tx_chns(common);
 		return ret;
+	}
 
 	/* If RX IRQ was disabled before suspend, keep it disabled */
 	for (i = 0; i < common->rx_ch_num_flows; i++) {