[PATCH iwl-next 3/8] e1000e: prevent race between PM and reset task
From: Matt Vollrath <hidden>
Date: 2026-08-30 23:22:33
Also in:
intel-wired-lan, linux-doc, lkml, stable
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
e1000e_down could be entered simultaneously by the reset task and the
runtime PM suspend callback. Prevent this by acquiring a runtime PM
reference in the reset task.
The intention is that:
* A reset attempted during runtime suspend should drop silently; the
interface is already going down.
* A runtime suspend attempted during a reset will be retried later.
* All callers of e1000e_down are now serialized.
Signed-off-by: Matt Vollrath <redacted>
Fixes: 23606cf5d119 ("e1000e / PCI / PM: Add basic runtime PM support (rev. 4)")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-5-fable
---
drivers/net/ethernet/intel/e1000e/netdev.c | 25 ++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 47ff3c6ab451..4c15ca307b08 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c@@ -6004,20 +6004,37 @@ static void e1000_tx_timeout(struct net_device *netdev, unsigned int __always_un static void e1000_reset_task(struct work_struct *work) { struct e1000_adapter *adapter; + struct device *dev; + int rc; + adapter = container_of(work, struct e1000_adapter, reset_task); + dev = &adapter->pdev->dev; rtnl_lock(); + + /* Runtime suspend downs the device without holding rtnl. Hold a + * runtime PM reference so it cannot start underneath the reset, and + * skip the reset if the device is already suspending or suspended: + * resuming resets the hardware anyway. + */ + rc = pm_runtime_get_if_active(dev); + if (!rc) + goto out_unlock; + /* don't run the task if already down */ - if (test_bit(__E1000_DOWN, &adapter->state)) { - rtnl_unlock(); - return; - } + if (test_bit(__E1000_DOWN, &adapter->state)) + goto out_put; if (!(adapter->flags & FLAG_RESTART_NOW)) { e1000e_dump(adapter); e_err("Reset adapter unexpectedly\n"); } e1000e_reinit_locked(adapter); + +out_put: + if (rc > 0) + pm_runtime_put(dev); +out_unlock: rtnl_unlock(); }
--
2.43.0