From e22b23f5888a065d084e87db1eec639c445e677f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 8 May 2024 06:45:04 -0700 Subject: [PATCH] eth: sungem: remove .ndo_poll_controller to avoid deadlocks [ Upstream commit ac0a230f719b02432d8c7eba7615ebd691da86f4 ] Erhard reports netpoll warnings from sungem: netpoll_send_skb_on_dev(): eth0 enabled interrupts in poll (gem_start_xmit+0x0/0x398) WARNING: CPU: 1 PID: 1 at net/core/netpoll.c:370 netpoll_send_skb+0x1fc/0x20c gem_poll_controller() disables interrupts, which may sleep. We can't sleep in netpoll, it has interrupts disabled completely. Strangely, gem_poll_controller() doesn't even poll the completions, and instead acts as if an interrupt has fired so it just schedules NAPI and exits. None of this has been necessary for years, since netpoll invokes NAPI directly. Fixes: fe09bb619096 ("sungem: Spring cleaning and GRO support") Reported-and-tested-by: Erhard Furtner Link: https://lore.kernel.org/all/20240428125306.2c3080ef@legion Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240508134504.3560956-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/sun/sungem.c | 14 -------------- 1 file changed, 14 deletions(-) diff --git a/drivers/net/ethernet/sun/sungem.c b/drivers/net/ethernet/sun/sungem.c index 58f142ee78a3..4d6a9f02c738 100644 --- a/drivers/net/ethernet/sun/sungem.c +++ b/drivers/net/ethernet/sun/sungem.c @@ -949,17 +949,6 @@ static irqreturn_t gem_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -#ifdef CONFIG_NET_POLL_CONTROLLER -static void gem_poll_controller(struct net_device *dev) -{ - struct gem *gp = netdev_priv(dev); - - disable_irq(gp->pdev->irq); - gem_interrupt(gp->pdev->irq, dev); - enable_irq(gp->pdev->irq); -} -#endif - static void gem_tx_timeout(struct net_device *dev, unsigned int txqueue) { struct gem *gp = netdev_priv(dev); @@ -2836,9 +2825,6 @@ static const struct net_device_ops gem_netdev_ops = { .ndo_change_mtu = gem_change_mtu, .ndo_validate_addr = eth_validate_addr, .ndo_set_mac_address = gem_set_mac_address, -#ifdef CONFIG_NET_POLL_CONTROLLER - .ndo_poll_controller = gem_poll_controller, -#endif }; static int gem_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)