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Unhandled fault during system suspend in sky2_shutdown

PATCH Sudeep Holla 2 participants 3 messages Apr 11, 2016 – Apr 12, 2016

Subsystems (3)
Networking Network drivers Marvell gigabit Ethernet drivers (skge/sky2)
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Sudeep Holla

author
#0 lore raw

Hi,

I am seeing unhandled fault during system suspend in sky2_shutdown.
I am not sure if it's something missing in the firmware, but just wanted
to check. I see that networkmanager is invoking calling to netlink_sendmsg which calls sky2_get_stats after the device is shutdown.

Unhandled fault: synchronous external abort (0x96000210) at 0xffff0000091c2918

Internal error: : 96000210 [#1] PREEMPT SMP
Modules linked in:
CPU: 3 PID: 2029 Comm: NetworkManager Not tainted 4.6.0-rc3 #126
Hardware name: ARM Juno development board (r2) (DT)
task: ffff80007a673000 ti: ffff800940b5c000 task.ti: ffff800940b5c000
PC is at sky2_get_stats+0x44/0x3b8
LR is at dev_get_stats+0x58/0xc8
 sky2_get_stats+0x44/0x3b8
 rtnl_fill_stats+0x20/0x138
 rtnl_fill_ifinfo+0x440/0xb38
 rtnl_getlink+0xe8/0x198
 rtnetlink_rcv_msg+0xe4/0x220
 netlink_rcv_skb+0xc4/0xf8
 rtnetlink_rcv+0x2c/0x40
 netlink_unicast+0x160/0x238
 netlink_sendmsg+0x2f0/0x358
 sock_sendmsg+0x18/0x30
 ___sys_sendmsg+0x204/0x218
 __sys_sendmsg+0x44/0x88
 SyS_sendmsg+0xc/0x18
 el0_svc_naked+0x24/0x28

The below patch is the hack I came up to check if the netdev is detached and unregistered, I no longer see the issue.

Regards,
Sudeep

-->8

drivers/net/ethernet/marvell/sky2.c +7 -0
index ec0a22119e09..0ff0434e32fc 100644
@@ -5220,6 +5220,13 @@ static SIMPLE_DEV_PM_OPS(sky2_pm_ops, sky2_suspend, sky2_resume);
 
 static void sky2_shutdown(struct pci_dev *pdev)
 {
+       struct sky2_hw *hw = pci_get_drvdata(pdev);
+       int i;
+
+       for (i = hw->ports - 1; i >= 0; --i) {
+               sky2_detach(hw->dev[i]);
+               unregister_netdev(hw->dev[i]);
+       }
        sky2_suspend(&pdev->dev);
        pci_wake_from_d3(pdev, device_may_wakeup(&pdev->dev));
        pci_set_power_state(pdev, PCI_D3hot);
#1 lore raw
Quoted 58 lines · On Mon, 11 Apr 2016 17:24:37 +0100 Sudeep Holla <[email protected]> wrote:

Hi,

I am seeing unhandled fault during system suspend in sky2_shutdown. I am not sure if it's something missing in the firmware, but just wanted to check. I see that networkmanager is invoking calling to netlink_sendmsg which calls sky2_get_stats after the device is shutdown.

Unhandled fault: synchronous external abort (0x96000210) at 0xffff0000091c2918

Internal error: : 96000210 [#1] PREEMPT SMP
Modules linked in:
CPU: 3 PID: 2029 Comm: NetworkManager Not tainted 4.6.0-rc3 #126
Hardware name: ARM Juno development board (r2) (DT)
task: ffff80007a673000 ti: ffff800940b5c000 task.ti: ffff800940b5c000
PC is at sky2_get_stats+0x44/0x3b8
LR is at dev_get_stats+0x58/0xc8
  sky2_get_stats+0x44/0x3b8
  rtnl_fill_stats+0x20/0x138
  rtnl_fill_ifinfo+0x440/0xb38
  rtnl_getlink+0xe8/0x198
  rtnetlink_rcv_msg+0xe4/0x220
  netlink_rcv_skb+0xc4/0xf8
  rtnetlink_rcv+0x2c/0x40
  netlink_unicast+0x160/0x238
  netlink_sendmsg+0x2f0/0x358
  sock_sendmsg+0x18/0x30
  ___sys_sendmsg+0x204/0x218
  __sys_sendmsg+0x44/0x88
  SyS_sendmsg+0xc/0x18
  el0_svc_naked+0x24/0x28

The below patch is the hack I came up to check if the netdev is detached and unregistered, I no longer see the issue.

Regards,
Sudeep

-->8

(quoted diff) +0 -0

w/drivers/net/ethernet/marvell/sky2.c
index ec0a22119e09..0ff0434e32fc 100644

drivers/net/ethernet/marvell/sky2.c +7 -0
@@ -5220,6 +5220,13 @@ static SIMPLE_DEV_PM_OPS(sky2_pm_ops, 
 sky2_suspend, sky2_resume);
 
  static void sky2_shutdown(struct pci_dev *pdev)
  {
+       struct sky2_hw *hw = pci_get_drvdata(pdev);
+       int i;
+
+       for (i = hw->ports - 1; i >= 0; --i) {
+               sky2_detach(hw->dev[i]);
+               unregister_netdev(hw->dev[i]);
+       }
         sky2_suspend(&pdev->dev);
         pci_wake_from_d3(pdev, device_may_wakeup(&pdev->dev));
Quoted 1 line
         pci_set_power_state(pdev, PCI_D3hot);

This is not the correct fix, the device is supposed to stay registered. The correct way to fix this would be to make get_stats ignore requests for device when suspended.

author
#2 lore raw
Quoted 3 lines · Stephen Hemminger

On Mon, 11 Apr 2016 17:24:37 +0100
Sudeep Holla <[email protected]> wrote:

[...]

Quoted 9 lines
Quoted 9 lines
(quoted diff) +0 -0

w/drivers/net/ethernet/marvell/sky2.c
index ec0a22119e09..0ff0434e32fc 100644

drivers/net/ethernet/marvell/sky2.c +0 -0
@@ -5220,6 +5220,13 @@ static SIMPLE_DEV_PM_OPS(sky2_pm_ops,
 sky2_suspend, sky2_resume);
Quoted 16 lines
Quoted 11 lines
drivers/net/ethernet/marvell/sky2.c +7 -0
   static void sky2_shutdown(struct pci_dev *pdev)
   {
+       struct sky2_hw *hw = pci_get_drvdata(pdev);
+       int i;
+
+       for (i = hw->ports - 1; i >= 0; --i) {
+               sky2_detach(hw->dev[i]);
+               unregister_netdev(hw->dev[i]);
+       }
          sky2_suspend(&pdev->dev);
          pci_wake_from_d3(pdev, device_may_wakeup(&pdev->dev));
Quoted 1 line
          pci_set_power_state(pdev, PCI_D3hot);

This is not the correct fix, the device is supposed to stay registered. The correct way to fix this would be to make get_stats ignore requests for device when suspended.

Yes I agree it's not correct fix. But I tried ignoring it in get_stat32 but the crash just moves the bug elsewhere. IMO patching all the places to check the suspended state might be bit heavy ?

E.g. with something like below the crash moves to sky2_get_eeprom_len function.

sky2_get_eeprom_len+0x10/0x30
dev_ethtool+0x29c/0x1d78
dev_ioctl+0x31c/0x5a8
sock_ioctl+0x2ac/0x310
do_vfs_ioctl+0xa4/0x750
SyS_ioctl+0x8c/0xa0
el0_svc_naked+0x24/0x2

Sorry if I am missing something fundamental, I am bit new to net drivers

Regards,
Sudeep

-->8

drivers/net/ethernet/marvell/sky2.c +2 -0
index ec0a22119e09..d4cfcd89e7e5 100644
@@ -5175,6 +5175,7 @@ static int sky2_suspend(struct device *dev)
        }
 
        sky2_power_aux(hw);
+       hw->suspended = true;
        rtnl_unlock();
 
        return 0;

@@ -5198,6 +5199,7 @@ static int sky2_resume(struct device *dev)
        }
 
        rtnl_lock();
+       hw->suspended = false;
        sky2_reset(hw);
        sky2_all_up(hw);
        rtnl_unlock();
drivers/net/ethernet/marvell/sky2.h +4 -0
index ec6dcd80152b..1386e5b635ff 100644
@@ -2308,6 +2308,7 @@ struct sky2_hw {
        wait_queue_head_t    msi_wait;
 
        char                 irq_name[0];
+       bool                 suspended;
 };
 
 static inline int sky2_is_copper(const struct sky2_hw *hw)

@@ -2378,6 +2379,9 @@ static inline u32 get_stats32(struct sky2_hw *hw, unsigned port, unsigned reg)
 {
        u32 val;
 
+       if (hw->suspended)
+               return 0;
+
        do {
                val = gma_read32(hw, port, reg);
        } while (gma_read32(hw, port, reg) != val);