[PATCH net-next v2] net: ti: icssg: Remove dedicated workqueue for ndo_set_rx_mode callback

[Kevin Hao <haokexin@gmail.com>]

Currently, both the icssg-prueth and icssg-prueth-sr1 drivers create
a dedicated 'emac->cmd_wq' workqueue.

In the icssg-prueth-sr1 driver, this workqueue is not utilized at all.

In the icssg-prueth driver, the workqueue is only used to execute the
actual processing of ndo_set_rx_mode. However, creating a dedicated
workqueue for such a simple use case is unnecessary. To simplify the
code, switch to using the system default workqueue instead.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
While addressing an issue in the cpsw driver, I based my fix [1] on the
implementation of the emac_ndo_set_rx_mode() function in icssg. During review,
Jakub pointed out that the dedicated workqueue for the ndo_set_rx_mode
callback might be unnecessary [2]. I subsequently used the system workqueue for
this purpose in the cpsw driver, and it performed as expected. Therefore,
I believe the same approach can be applied to the icssg driver. This
patch aim to remove this dedicated workqueue for icssg drivers.

Please note: I do not have access to a board that supports the CSSG PRU
Ethernet controller, so this change has only been build-tested.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=c0b5dc73a38f954e780f93a549b8fe225235c07a
[2] https://lore.kernel.org/all/20260127190836.6a420768@kernel.org/
---
Cc: MD Danish Anwar <danishanwar@ti.com>
Cc: Roger Quadros <rogerq@kernel.org>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Meghana Malladi <m-malladi@ti.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Cc: Himanshu Mittal <h-mittal1@ti.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Cc: linux-arm-kernel@lists.infradead.org
---
Changes in v2:
- Given the issue identified by the AI [3], squash these two patches into
  one as suggested by Jakub.

- Include the cpsw fix link and the link to Jakub's email in the cover letter,
  as requested by Meghana.

- Link to v1: https://lore.kernel.org/r/20260204-icssg-prueth-workqueue-v1-0-9a892f4b293d@gmail.com

[3] https://netdev-ai.bots.linux.dev/ai-review.html?id=02da18ab-455d-4d98-88bb-d8a975623c3f
---
 drivers/net/ethernet/ti/icssg/icssg_common.c     |  1 -
 drivers/net/ethernet/ti/icssg/icssg_prueth.c     | 13 ++++---------
 drivers/net/ethernet/ti/icssg/icssg_prueth.h     |  1 -
 drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c |  9 +--------
 4 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c
index 090aa74d3ce7257ae52158b2ff9a2a1239bfcfc8..0cf9dfe0fa362b4ff986b6815952f95b79cb476d 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_common.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_common.c
@@ -1720,7 +1720,6 @@ void prueth_netdev_exit(struct prueth *prueth,
 	netif_napi_del(&emac->napi_rx);
 
 	pruss_release_mem_region(prueth->pruss, &emac->dram);
-	destroy_workqueue(emac->cmd_wq);
 	free_netdev(emac->ndev);
 	prueth->emac[mac] = NULL;
 }
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
index f65041662173c1968f7e70dc4a3d897523f24095..0939994c932f5322eebbaa1b2fe43e20d3dca5ae 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
@@ -1099,7 +1099,7 @@ static void emac_ndo_set_rx_mode(struct net_device *ndev)
 {
 	struct prueth_emac *emac = netdev_priv(ndev);
 
-	queue_work(emac->cmd_wq, &emac->rx_mode_work);
+	schedule_work(&emac->rx_mode_work);
 }
 
 static netdev_features_t emac_ndo_fix_features(struct net_device *ndev,
@@ -1451,11 +1451,6 @@ static int prueth_netdev_init(struct prueth *prueth,
 	emac->port_id = port;
 	emac->xdp_prog = NULL;
 	emac->ndev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
-	emac->cmd_wq = create_singlethread_workqueue("icssg_cmd_wq");
-	if (!emac->cmd_wq) {
-		ret = -ENOMEM;
-		goto free_ndev;
-	}
 	INIT_WORK(&emac->rx_mode_work, emac_ndo_set_rx_mode_work);
 
 	INIT_DELAYED_WORK(&emac->stats_work, icssg_stats_work_handler);
@@ -1467,7 +1462,7 @@ static int prueth_netdev_init(struct prueth *prueth,
 	if (ret) {
 		dev_err(prueth->dev, "unable to get DRAM: %d\n", ret);
 		ret = -ENOMEM;
-		goto free_wq;
+		goto free_ndev;
 	}
 
 	emac->tx_ch_num = 1;
@@ -1566,8 +1561,6 @@ static int prueth_netdev_init(struct prueth *prueth,
 
 free:
 	pruss_release_mem_region(prueth->pruss, &emac->dram);
-free_wq:
-	destroy_workqueue(emac->cmd_wq);
 free_ndev:
 	emac->ndev = NULL;
 	prueth->emac[mac] = NULL;
@@ -2236,6 +2229,7 @@ static int prueth_probe(struct platform_device *pdev)
 			prueth->emac[i]->ndev->phydev = NULL;
 		}
 		unregister_netdev(prueth->registered_netdevs[i]);
+		disable_work_sync(&prueth->emac[i]->rx_mode_work);
 	}
 
 netdev_exit:
@@ -2295,6 +2289,7 @@ static void prueth_remove(struct platform_device *pdev)
 		phy_disconnect(prueth->emac[i]->ndev->phydev);
 		prueth->emac[i]->ndev->phydev = NULL;
 		unregister_netdev(prueth->registered_netdevs[i]);
+		disable_work_sync(&prueth->emac[i]->rx_mode_work);
 	}
 
 	for (i = 0; i < PRUETH_NUM_MACS; i++) {
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index 10eadd35665045a98a0c0a639606b7c2691195de..3d94fa5a7ac10992d35fdb63458f8cb6eb3a5a22 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -236,7 +236,6 @@ struct prueth_emac {
 	/* Mutex to serialize access to firmware command interface */
 	struct mutex cmd_lock;
 	struct work_struct rx_mode_work;
-	struct workqueue_struct	*cmd_wq;
 
 	struct pruss_mem_region dram;
 
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c b/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c
index 7bb4f0d850cc72d997e5ead38cf56f1dbc2355a1..b8115ca47082f9676067bb65c6eb3a441290fd7c 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c
@@ -783,11 +783,6 @@ static int prueth_netdev_init(struct prueth *prueth,
 	emac->prueth = prueth;
 	emac->ndev = ndev;
 	emac->port_id = port;
-	emac->cmd_wq = create_singlethread_workqueue("icssg_cmd_wq");
-	if (!emac->cmd_wq) {
-		ret = -ENOMEM;
-		goto free_ndev;
-	}
 
 	INIT_DELAYED_WORK(&emac->stats_work, icssg_stats_work_handler);
 
@@ -798,7 +793,7 @@ static int prueth_netdev_init(struct prueth *prueth,
 	if (ret) {
 		dev_err(prueth->dev, "unable to get DRAM: %d\n", ret);
 		ret = -ENOMEM;
-		goto free_wq;
+		goto free_ndev;
 	}
 
 	/* SR1.0 uses a dedicated high priority channel
@@ -883,8 +878,6 @@ static int prueth_netdev_init(struct prueth *prueth,
 
 free:
 	pruss_release_mem_region(prueth->pruss, &emac->dram);
-free_wq:
-	destroy_workqueue(emac->cmd_wq);
 free_ndev:
 	emac->ndev = NULL;
 	prueth->emac[mac] = NULL;

---
base-commit: 0f8a890c4524d6e4013ff225e70de2aed7e6d726
change-id: 20260203-icssg-prueth-workqueue-f460eba72132

Best regards,
-- 
Kevin Hao <haokexin@gmail.com>