From: Heiner Kallweit <hkallweit1@xxxxxxxxx> Recent net core changes caused an issue with few Intel drivers (reportedly igb), where taking RTNL in RPM resume path results in a deadlock. See [0] for a bug report. I don't think the core changes are wrong, but taking RTNL in RPM resume path isn't needed. The Intel drivers are the only ones doing this. See [1] for a discussion on the issue. Following patch changes the RPM resume path to not take RTNL. [0] https://bugzilla.kernel.org/show_bug.cgi?id=215129 [1] https://lore.kernel.org/netdev/20211125074949.5f897431@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/t/ Cc: stable@xxxxxxxxxxxxxxx Fixes: bd869245a3dc ("net: core: try to runtime-resume detached device in __dev_open") Fixes: f32a21376573 ("ethtool: runtime-resume netdev parent before ethtool ioctl ops") Tested-by: Martin Stolpe <martin.stolpe@xxxxxxxxx> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> --- drivers/net/ethernet/intel/igb/igb_main.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index b597b8bfb910..446894dde182 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -9254,7 +9254,7 @@ static int __maybe_unused igb_suspend(struct device *dev) return __igb_shutdown(to_pci_dev(dev), NULL, 0); } -static int __maybe_unused igb_resume(struct device *dev) +static int __maybe_unused __igb_resume(struct device *dev, bool rpm) { struct pci_dev *pdev = to_pci_dev(dev); struct net_device *netdev = pci_get_drvdata(pdev); @@ -9297,17 +9297,24 @@ static int __maybe_unused igb_resume(struct device *dev) wr32(E1000_WUS, ~0); - rtnl_lock(); + if (!rpm) + rtnl_lock(); if (!err && netif_running(netdev)) err = __igb_open(netdev, true); if (!err) netif_device_attach(netdev); - rtnl_unlock(); + if (!rpm) + rtnl_unlock(); return err; } +static int __maybe_unused igb_resume(struct device *dev) +{ + return __igb_resume(dev, false); +} + static int __maybe_unused igb_runtime_idle(struct device *dev) { struct net_device *netdev = dev_get_drvdata(dev); @@ -9326,7 +9333,7 @@ static int __maybe_unused igb_runtime_suspend(struct device *dev) static int __maybe_unused igb_runtime_resume(struct device *dev) { - return igb_resume(dev); + return __igb_resume(dev, true); } static void igb_shutdown(struct pci_dev *pdev) @@ -9442,7 +9449,7 @@ static pci_ers_result_t igb_io_error_detected(struct pci_dev *pdev, * @pdev: Pointer to PCI device * * Restart the card from scratch, as if from a cold-boot. Implementation - * resembles the first-half of the igb_resume routine. + * resembles the first-half of the __igb_resume routine. **/ static pci_ers_result_t igb_io_slot_reset(struct pci_dev *pdev) { @@ -9482,7 +9489,7 @@ static pci_ers_result_t igb_io_slot_reset(struct pci_dev *pdev) * * This callback is called when the error recovery driver tells us that * its OK to resume normal operation. Implementation resembles the - * second-half of the igb_resume routine. + * second-half of the __igb_resume routine. */ static void igb_io_resume(struct pci_dev *pdev) { -- 2.31.1
