Patch "e100: fix device suspend/resume" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    e100: fix device suspend/resume

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     e100-fix-device-suspend-resume.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6e5ac2c16fc2dfc1faf51ede0307bdf9221a4407
Author: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
Date:   Wed Nov 17 12:59:52 2021 -0800

    e100: fix device suspend/resume
    
    [ Upstream commit 5d2ca2e12dfb2aff3388ca57b06f570fa6206ced ]
    
    As reported in [1], e100 was no longer working for suspend/resume
    cycles. The previous commit mentioned in the fixes appears to have
    broken things and this attempts to practice best known methods for
    device power management and keep wake-up working while allowing
    suspend/resume to work. To do this, I reorder a little bit of code
    and fix the resume path to make sure the device is enabled.
    
    [1] https://bugzilla.kernel.org/show_bug.cgi?id=214933
    
    Fixes: 69a74aef8a18 ("e100: use generic power management")
    Cc: Vaibhav Gupta <vaibhavgupta40@xxxxxxxxx>
    Reported-by: Alexey Kuznetsov <axet@xxxxxx>
    Signed-off-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
    Tested-by: Alexey Kuznetsov <axet@xxxxxx>
    Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c
index ee86ea12fa379..9295a9a1efc73 100644
--- a/drivers/net/ethernet/intel/e100.c
+++ b/drivers/net/ethernet/intel/e100.c
@@ -2997,9 +2997,10 @@ static void __e100_shutdown(struct pci_dev *pdev, bool *enable_wake)
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct nic *nic = netdev_priv(netdev);
 
+	netif_device_detach(netdev);
+
 	if (netif_running(netdev))
 		e100_down(nic);
-	netif_device_detach(netdev);
 
 	if ((nic->flags & wol_magic) | e100_asf(nic)) {
 		/* enable reverse auto-negotiation */
@@ -3016,7 +3017,7 @@ static void __e100_shutdown(struct pci_dev *pdev, bool *enable_wake)
 		*enable_wake = false;
 	}
 
-	pci_clear_master(pdev);
+	pci_disable_device(pdev);
 }
 
 static int __e100_power_off(struct pci_dev *pdev, bool wake)
@@ -3036,8 +3037,6 @@ static int __maybe_unused e100_suspend(struct device *dev_d)
 
 	__e100_shutdown(to_pci_dev(dev_d), &wake);
 
-	device_wakeup_disable(dev_d);
-
 	return 0;
 }
 
@@ -3045,6 +3044,14 @@ static int __maybe_unused e100_resume(struct device *dev_d)
 {
 	struct net_device *netdev = dev_get_drvdata(dev_d);
 	struct nic *nic = netdev_priv(netdev);
+	int err;
+
+	err = pci_enable_device(to_pci_dev(dev_d));
+	if (err) {
+		netdev_err(netdev, "Resume cannot enable PCI device, aborting\n");
+		return err;
+	}
+	pci_set_master(to_pci_dev(dev_d));
 
 	/* disable reverse auto-negotiation */
 	if (nic->phy == phy_82552_v) {
@@ -3056,10 +3063,11 @@ static int __maybe_unused e100_resume(struct device *dev_d)
 		           smartspeed & ~(E100_82552_REV_ANEG));
 	}
 
-	netif_device_attach(netdev);
 	if (netif_running(netdev))
 		e100_up(nic);
 
+	netif_device_attach(netdev);
+
 	return 0;
 }