igb device gets runtime suspended when there's no link partner. We can't
get correct speed under that state:
$ cat /sys/class/net/enp3s0/speed
1000
In addition to that, an error can also be spotted in dmesg:
[ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost
Since device can only be runtime suspended when there's no link partner,
we can skip reading register and let the following logic set speed and
duplex with correct status.
The more generic approach will be wrap get_link_ksettings() with begin()
and complete() callbacks. However, for this particular issue, begin()
calls igb_runtime_resume() , which tries to rtnl_lock() while the lock
is already hold by upper ethtool layer.
So let's take this approach until the igb_runtime_resume() no longer
needs to hold rtnl_lock.
Cc: Jeff Kirsher <[email protected]>
Cc: Aaron Brown <[email protected]>
Suggested-by: Alexander Duyck <[email protected]>
Signed-off-by: Kai-Heng Feng <[email protected]>
---
v2:
- Don't early return the routine so other info can be set.
drivers/net/ethernet/intel/igb/igb_ethtool.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 39d3b76a6f5d..2cd003c5ad43 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -143,7 +143,8 @@ static int igb_get_link_ksettings(struct net_device *netdev,
u32 speed;
u32 supported, advertising;
- status = rd32(E1000_STATUS);
+ status = pm_runtime_suspended(&adapter->pdev->dev) ?
+ 0 : rd32(E1000_STATUS);
if (hw->phy.media_type == e1000_media_type_copper) {
supported = (SUPPORTED_10baseT_Half |
--
2.17.1
> From: Kai-Heng Feng <[email protected]>
> Sent: Monday, May 4, 2020 9:02 PM
> To: Kirsher, Jeffrey T <[email protected]>
> Cc: Kai-Heng Feng <[email protected]>; Brown, Aaron F
> <[email protected]>; David S. Miller <[email protected]>;
> moderated list:INTEL ETHERNET DRIVERS <[email protected]>;
> open list:NETWORKING DRIVERS <[email protected]>; open list <linux-
> [email protected]>
> Subject: [PATCH v2] igb: Report speed and duplex as unknown when device is
> runtime suspended
>
> igb device gets runtime suspended when there's no link partner. We can't
> get correct speed under that state:
> $ cat /sys/class/net/enp3s0/speed
> 1000
>
> In addition to that, an error can also be spotted in dmesg:
> [ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost
>
> Since device can only be runtime suspended when there's no link partner,
> we can skip reading register and let the following logic set speed and
> duplex with correct status.
>
> The more generic approach will be wrap get_link_ksettings() with begin()
> and complete() callbacks. However, for this particular issue, begin()
> calls igb_runtime_resume() , which tries to rtnl_lock() while the lock
> is already hold by upper ethtool layer.
>
> So let's take this approach until the igb_runtime_resume() no longer
> needs to hold rtnl_lock.
>
> Cc: Jeff Kirsher <[email protected]>
> Cc: Aaron Brown <[email protected]>
> Suggested-by: Alexander Duyck <[email protected]>
> Signed-off-by: Kai-Heng Feng <[email protected]>
> ---
> v2:
> - Don't early return the routine so other info can be set.
>
> drivers/net/ethernet/intel/igb/igb_ethtool.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
Tested-by: Aaron Brown <[email protected]>