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authorBenjamin Poirier <bpoirier@suse.com>2017-07-21 11:36:26 -0700
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2017-10-10 08:35:01 -0700
commit19110cfbb34d4af0cdfe14cd243f3b09dc95b013 (patch)
treed3e23b6c58c955bc6e38c0a31d3a0d1f7ad8de99
parentd3509f8bc7b0560044c15f0e3ecfde1d9af757a6 (diff)
e1000e: Separate signaling for link check/link up
Lennart reported the following race condition: \ e1000_watchdog_task \ e1000e_has_link \ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link /* link is up */ mac->get_link_status = false; /* interrupt */ \ e1000_msix_other hw->mac.get_link_status = true; link_active = !hw->mac.get_link_status /* link_active is false, wrongly */ This problem arises because the single flag get_link_status is used to signal two different states: link status needs checking and link status is down. Avoid the problem by using the return value of .check_for_link to signal the link status to e1000e_has_link(). Reported-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca> Signed-off-by: Benjamin Poirier <bpoirier@suse.com> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
-rw-r--r--drivers/net/ethernet/intel/e1000e/mac.c11
-rw-r--r--drivers/net/ethernet/intel/e1000e/netdev.c2
2 files changed, 9 insertions, 4 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index b322011ec282..f457c5703d0c 100644
--- 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 e1000_hw *hw)
* 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)
{
@@ -423,7 +426,7 @@ s32 e1000e_check_for_copper_link(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
@@ -461,10 +464,12 @@ s32 e1000e_check_for_copper_link(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;
}
/**
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index a740de6a30b0..0a5f95ab0d3c 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5081,7 +5081,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter)
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;
}