On 2017/12/07 20:02, Ben Hutchings wrote:
On Tue, 2017-11-28 at 11:23 +0100, Greg Kroah-Hartman wrote:
4.4-stable review patch. If anyone has any objections, please let me know.
From: Benjamin Poirier bpoirier@suse.com
commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013 upstream.
[...]
--- a/drivers/net/ethernet/intel/e1000e/mac.c +++ b/drivers/net/ethernet/intel/e1000e/mac.c @@ -410,6 +410,9 @@ void e1000e_clear_hw_cntrs_base(struct e * Checks to see of the link status of the hardware has changed. If a * change in link status has been detected, then we read the PHY registers * to get the current speed/duplex if link exists.
- * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- * up).
**/ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) {
[...]
--- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5017,7 +5017,7 @@ static bool e1000e_has_link(struct e1000
case e1000_media_type_copper: if (hw->mac.get_link_status) { ret_val = hw->mac.ops.check_for_link(hw);
link_active = !hw->mac.get_link_status;
link_active = ret_val > 0;} else { link_active = true; }
As this change in e1000e_has_link() is conditional only on the media type, doesn't e1000_check_for_copper_link_ich8lan() also need to be changed to return 1 for link up?
You're right. I looked at it again, in the commit log I wrote that "hw->mac.ops.check_for_link(hw) === e1000e_check_for_copper_link" which is true for the race condition reported (because that's the function in use on adapters that have msix vectors mac.type == e1000_82574) but not generally true. The other check_for_link callback needs to be adjusted likewise.
However, I happen to have a I218-LM (e1000_pch_lpt) so I tested 4.14.3 and this error only delays link up, it doesn't prevent it. e1000_check_for_copper_link_ich8lan() sets mac->get_link_status = false; and on the next watchdog execution, we fall in the second branch of the following e1000e_has_link code:
case e1000_media_type_copper: if (hw->mac.get_link_status) { ret_val = hw->mac.ops.check_for_link(hw); link_active = ret_val > 0; } else { link_active = true;
OTOH, there are multiple reports in https://bugzilla.kernel.org/show_bug.cgi?id=198047 that reverting 830466993daf ("e1000e: Separate signaling for link check/link up") fixes the issue so there's something I'm missing.
Gabriel and Christian, can you test the following patch?
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c index d6d4ed7acf03..31277d3bb7dc 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c @@ -1367,6 +1367,9 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force) * Checks to see of the link status of the hardware has changed. If a * change in link status has been detected, then we read the PHY registers * to get the current speed/duplex if link exists. + * + * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link + * up). **/ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) { @@ -1382,7 +1385,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) * Change or Rx Sequence Error interrupt. */ if (!mac->get_link_status) - return 0; + return 1;
/* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex @@ -1613,10 +1616,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) * different link partner. */ ret_val = e1000e_config_fc_after_link_up(hw); - if (ret_val) + if (ret_val) { e_dbg("Error configuring flow control\n"); + return ret_val; + }
- return ret_val; + return 1; }
static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)