From: Heiner Kallweit hkallweit1@gmail.com
[ Upstream commit ac8c58f5b535d6272324e2b8b4a0454781c9147e ]
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@kicinski-fedora-pc1c0...
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@gmail.com Signed-off-by: Heiner Kallweit hkallweit1@gmail.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Link: https://lore.kernel.org/r/20211220201844.2714498-1-anthony.l.nguyen@intel.co... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1662c0985eca4..f854d41c6c94d 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -9260,7 +9260,7 @@ 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); @@ -9303,17 +9303,24 @@ 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); @@ -9332,7 +9339,7 @@ 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) @@ -9448,7 +9455,7 @@ 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) { @@ -9488,7 +9495,7 @@ 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) {