[Intel-wired-lan] [PATCH] igc: fix netdev not re-attached after resume if interface is down

[Intel-wired-lan] [PATCH] igc: fix netdev not re-attached after resume if interface is down

[Philipp David via Intel-wired-lan]

__igc_resume() calls netif_device_attach() only inside the
netif_running() branch, so an interface that was down during suspend
is never re-attached on resume. It then stays in the not-present state
that __igc_shutdown() set via netif_device_detach(): ethtool reports
ENODEV and every attempt to bring the interface up fails the
netif_device_present() check in __dev_open() with -ENODEV, silently,
since __igc_resume() returns 0. Only reloading the driver recovers the
device.

This is easy to hit in practice because NetworkManager brings managed
interfaces down before sleep unless Wake-on-LAN is configured, making
the adapter unusable after every suspend/resume cycle with WoL
disabled.

Re-attach the netdev on every successful resume, as igb and e1000e do.

Fixes: 6f31d6b643a3 ("igc: Refactor runtime power management flow")
Cc: stable@vger.kernel.org
Signed-off-by: Philipp David <pd-lkml@3b.pm>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 2c9e2dfd8499..e777c2df0b73 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -7586,11 +7586,13 @@ static int __igc_resume(struct device *dev, bool rpm)
 		err = __igc_open(netdev, true);
 		if (!rpm)
 			rtnl_unlock();
-		if (!err)
-			netif_device_attach(netdev);
+		if (err)
+			return err;
 	}
 
-	return err;
+	netif_device_attach(netdev);
+
+	return 0;
 }
 
 static int igc_resume(struct device *dev)
-- 
2.54.0

Re: [Intel-wired-lan] [PATCH] igc: fix netdev not re-attached after resume if interface is down

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Philipp David via Intel-wired-lan
> Sent: Friday, July 17, 2026 11:22 AM
> To: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org
> Cc: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; David S . Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; Philipp David <pd-lkml@3b.pm>;
> stable@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH] igc: fix netdev not re-attached
> after resume if interface is down
> 
> __igc_resume() calls netif_device_attach() only inside the
> netif_running() branch, so an interface that was down during suspend
> is never re-attached on resume. It then stays in the not-present state
> that __igc_shutdown() set via netif_device_detach(): ethtool reports
> ENODEV and every attempt to bring the interface up fails the
> netif_device_present() check in __dev_open() with -ENODEV, silently,
> since __igc_resume() returns 0. Only reloading the driver recovers the
> device.
> 
> This is easy to hit in practice because NetworkManager brings managed
> interfaces down before sleep unless Wake-on-LAN is configured, making
> the adapter unusable after every suspend/resume cycle with WoL
> disabled.
> 
> Re-attach the netdev on every successful resume, as igb and e1000e do.
> 
> Fixes: 6f31d6b643a3 ("igc: Refactor runtime power management flow")
> Cc: stable@vger.kernel.org
> Signed-off-by: Philipp David <pd-lkml@3b.pm>
> ---
>  drivers/net/ethernet/intel/igc/igc_main.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
> b/drivers/net/ethernet/intel/igc/igc_main.c
> index 2c9e2dfd8499..e777c2df0b73 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -7586,11 +7586,13 @@ static int __igc_resume(struct device *dev,
> bool rpm)
>  		err = __igc_open(netdev, true);
>  		if (!rpm)
>  			rtnl_unlock();
> -		if (!err)
> -			netif_device_attach(netdev);
> +		if (err)
> +			return err;
>  	}
> 
> -	return err;
> +	netif_device_attach(netdev);
> +
> +	return 0;
>  }
> 
>  static int igc_resume(struct device *dev)
> --
> 2.54.0

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Re: [Intel-wired-lan] [PATCH] igc: fix netdev not re-attached after resume if interface is down

[Ruinskiy, Dima]

On 23/07/2026 12:18, Loktionov, Aleksandr wrote:
> 
> 
>> -----Original Message-----
>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
>> Of Philipp David via Intel-wired-lan
>> Sent: Friday, July 17, 2026 11:22 AM
>> To: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org
>> Cc: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
>> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
>> <andrew+netdev@lunn.ch>; David S . Miller <davem@davemloft.net>; Eric
>> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
>> Abeni <pabeni@redhat.com>; Philipp David <pd-lkml@3b.pm>;
>> stable@vger.kernel.org
>> Subject: [Intel-wired-lan] [PATCH] igc: fix netdev not re-attached
>> after resume if interface is down
>>
>> __igc_resume() calls netif_device_attach() only inside the
>> netif_running() branch, so an interface that was down during suspend
>> is never re-attached on resume. It then stays in the not-present state
>> that __igc_shutdown() set via netif_device_detach(): ethtool reports
>> ENODEV and every attempt to bring the interface up fails the
>> netif_device_present() check in __dev_open() with -ENODEV, silently,
>> since __igc_resume() returns 0. Only reloading the driver recovers the
>> device.
>>
>> This is easy to hit in practice because NetworkManager brings managed
>> interfaces down before sleep unless Wake-on-LAN is configured, making
>> the adapter unusable after every suspend/resume cycle with WoL
>> disabled.
>>
>> Re-attach the netdev on every successful resume, as igb and e1000e do.
>>
>> Fixes: 6f31d6b643a3 ("igc: Refactor runtime power management flow")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Philipp David <pd-lkml@3b.pm>
>> ---
>>   drivers/net/ethernet/intel/igc/igc_main.c | 8 +++++---
>>   1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
>> b/drivers/net/ethernet/intel/igc/igc_main.c
>> index 2c9e2dfd8499..e777c2df0b73 100644
>> --- a/drivers/net/ethernet/intel/igc/igc_main.c
>> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
>> @@ -7586,11 +7586,13 @@ static int __igc_resume(struct device *dev,
>> bool rpm)
>>   		err = __igc_open(netdev, true);
>>   		if (!rpm)
>>   			rtnl_unlock();
>> -		if (!err)
>> -			netif_device_attach(netdev);
>> +		if (err)
>> +			return err;
>>   	}
>>
>> -	return err;
>> +	netif_device_attach(netdev);
>> +
>> +	return 0;
>>   }
>>
>>   static int igc_resume(struct device *dev)
>> --
>> 2.54.0
> 
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Dima Ruinskiy <dima.ruinskiy@intel.com>