[PATCH net-next] net: airoha: Wait for TX to complete in airoha_dev_stop()

Lorenzo Bianconi
2026-04-10T22:06:10Z

Wait for TX to complete in airoha_dev_stop routine before stopping the
TX DMA and run airoha_qdma_cleanup_tx_queue routine. Moreover,
start/stop TX/RX NAPIs in ndo_open()/ndo_stop() callbacks in order to be
sure the TX NAPIs have completed before stopping the TX DMA engine in
airoha_dev_stop routine.
Please note this patch on the commit 'b1c803d5c816 ("net: airoha: Rework
the code flow in airoha_remove() and in airoha_probe() error path")'
that is available only in net-next tree at the moment.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
drivers/net/ethernet/airoha/airoha_eth.c | 44 +++++++++++++++++---------------
1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 8e4b043af4bc..9e40c8f375c1 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -1662,10 +1662,12 @@ static int airoha_dev_open(struct net_device *dev)
FIELD_PREP(GDM_SHORT_LEN_MASK, 60) |
FIELD_PREP(GDM_LONG_LEN_MASK, len));

- airoha_qdma_set(qdma, REG_QDMA_GLOBAL_CFG,
- GLOBAL_CFG_TX_DMA_EN_MASK |
- GLOBAL_CFG_RX_DMA_EN_MASK);
- atomic_inc(&qdma->users);
+ if (!atomic_fetch_inc(&qdma->users)) {
+ airoha_qdma_set(qdma, REG_QDMA_GLOBAL_CFG,
+ GLOBAL_CFG_TX_DMA_EN_MASK |
+ GLOBAL_CFG_RX_DMA_EN_MASK);
+ airoha_qdma_start_napi(qdma);
+ }

if (port->id == AIROHA_GDM2_IDX &&
airoha_ppe_is_enabled(qdma->eth, 1)) {
@@ -1684,18 +1686,26 @@ static int airoha_dev_stop(struct net_device *dev)
struct airoha_qdma *qdma = port->qdma;
int i, err;

- netif_tx_disable(dev);
err = airoha_set_vip_for_gdm_port(port, false);
if (err)
return err;

- for (i = 0; i < ARRAY_SIZE(qdma->q_tx); i++)
- netdev_tx_reset_subqueue(dev, i);
-
airoha_set_gdm_port_fwd_cfg(qdma->eth, REG_GDM_FWD_CFG(port->id),
FE_PSE_PORT_DROP);

+ netif_tx_disable(dev);
if (atomic_dec_and_test(&qdma->users)) {
+ u32 val;
+
+ /* Wait for TX to complete */
+ err = read_poll_timeout(airoha_qdma_rr, val,
+ !(val & GLOBAL_CFG_TX_DMA_BUSY_MASK),
+ USEC_PER_MSEC, 100 * USEC_PER_MSEC,
+ false, qdma, REG_QDMA_GLOBAL_CFG);
+ if (err)
+ return err;
+
+ airoha_qdma_stop_napi(qdma);
airoha_qdma_clear(qdma, REG_QDMA_GLOBAL_CFG,
GLOBAL_CFG_TX_DMA_EN_MASK |
GLOBAL_CFG_RX_DMA_EN_MASK);
@@ -1708,6 +1718,9 @@ static int airoha_dev_stop(struct net_device *dev)
}
}

+ for (i = 0; i < ARRAY_SIZE(qdma->q_tx); i++)
+ netdev_tx_reset_subqueue(dev, i);
+
return 0;
}

@@ -3048,9 +3061,6 @@ static int airoha_probe(struct platform_device *pdev)
if (err)
goto error_netdev_free;

- for (i = 0; i < ARRAY_SIZE(eth->qdma); i++)
- airoha_qdma_start_napi(&eth->qdma[i]);
-
for_each_child_of_node(pdev->dev.of_node, np) {
if (!of_device_is_compatible(np, "airoha,eth-mac"))
continue;
@@ -3061,20 +3071,17 @@ static int airoha_probe(struct platform_device *pdev)
err = airoha_alloc_gdm_port(eth, np);
if (err) {
of_node_put(np);
- goto error_napi_stop;
+ goto error_netdev_unregister;
}
}

err = airoha_register_gdm_devices(eth);
if (err)
- goto error_napi_stop;
+ goto error_netdev_unregister;

return 0;

-error_napi_stop:
- for (i = 0; i < ARRAY_SIZE(eth->qdma); i++)
- airoha_qdma_stop_napi(&eth->qdma[i]);
-
+error_netdev_unregister:
for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
struct airoha_gdm_port *port = eth->ports[i];

@@ -3098,9 +3105,6 @@ static void airoha_remove(struct platform_device *pdev)
struct airoha_eth *eth = platform_get_drvdata(pdev);
int i;

- for (i = 0; i < ARRAY_SIZE(eth->qdma); i++)
- airoha_qdma_stop_napi(&eth->qdma[i]);
-
for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
struct airoha_gdm_port *port = eth->ports[i];

---
base-commit: 42f9b4c6ef19e71d2c7d9bfd3c5037d4fe434ad7
change-id: 20260410-airoha-fix-ndo_stop-ebbf3c724ae0

Best regards,
--
Lorenzo Bianconi <lorenzo@kernel.org>