diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index 2ea5dfe85539..ad0fdc4133fb 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -5341,6 +5341,22 @@ static int mtk_probe(struct platform_device *pdev) } } + /* we run 2 devices on the same DMA ring so we need a dummy device + * for NAPI to work. Allocate it before registering the netdevs so a + * concurrent ndo_open (e.g. netifd bringing the first netdev up the + * instant it is registered) never observes eth->dummy_dev == NULL in + * mtk_dma_init() -> mtk_rx_alloc() -> __xdp_rxq_info_reg() (net/core/xdp.c + * "Missing net_device from driver") and fails the first open. + */ + eth->dummy_dev = alloc_netdev_dummy(0); + if (!eth->dummy_dev) { + err = -ENOMEM; + dev_err(eth->dev, "failed to allocated dummy device\n"); + goto err_unreg_netdev; + } + netif_napi_add(eth->dummy_dev, ð->tx_napi, mtk_napi_tx); + netif_napi_add(eth->dummy_dev, ð->rx_napi, mtk_napi_rx); + for (i = 0; i < MTK_MAX_DEVS; i++) { if (!eth->netdev[i]) continue; @@ -5355,18 +5371,6 @@ static int mtk_probe(struct platform_device *pdev) eth->netdev[i]->base_addr, eth->irq[MTK_FE_IRQ_SHARED]); } - /* we run 2 devices on the same DMA ring so we need a dummy device - * for NAPI to work - */ - eth->dummy_dev = alloc_netdev_dummy(0); - if (!eth->dummy_dev) { - err = -ENOMEM; - dev_err(eth->dev, "failed to allocated dummy device\n"); - goto err_unreg_netdev; - } - netif_napi_add(eth->dummy_dev, ð->tx_napi, mtk_napi_tx); - netif_napi_add(eth->dummy_dev, ð->rx_napi, mtk_napi_rx); - platform_set_drvdata(pdev, eth); schedule_delayed_work(ð->reset.monitor_work, MTK_DMA_MONITOR_TIMEOUT); @@ -5376,6 +5380,16 @@ static int mtk_probe(struct platform_device *pdev) err_unreg_netdev: mtk_unreg_dev(eth); err_deinit_ppe: + /* A netdev opened while probe was still registering can have queued + * the frame-engine reset worker, which takes rtnl and drives the + * hardware; cancel it before anything below is torn down. + */ + cancel_work_sync(ð->pending_work); + if (eth->dummy_dev) { + netif_napi_del(ð->tx_napi); + netif_napi_del(ð->rx_napi); + free_netdev(eth->dummy_dev); + } mtk_ppe_deinit(eth); mtk_mdio_cleanup(eth); err_free_dev: