From 165ae7a8feb53dc47fb041357e4b253bfc927cf9 Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng Date: Tue, 5 May 2020 12:01:54 +0800 Subject: [PATCH] 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: stable Suggested-by: Alexander Duyck Signed-off-by: Kai-Heng Feng Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- 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 39d3b76a6f5d4d..2cd003c5ad4319 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 |