diff options
| author | Benjamin Poirier <bpoirier@suse.com> | 2017-07-21 21:36:26 +0300 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2017-10-10 18:35:01 +0300 |
| commit | 19110cfbb34d4af0cdfe14cd243f3b09dc95b013 (patch) | |
| tree | d3e23b6c58c955bc6e38c0a31d3a0d1f7ad8de99 /drivers/net/ethernet/intel/e1000e/mac.c | |
| parent | d3509f8bc7b0560044c15f0e3ecfde1d9af757a6 (diff) | |
| download | linux-19110cfbb34d4af0cdfe14cd243f3b09dc95b013.tar.xz | |
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>
Diffstat (limited to 'drivers/net/ethernet/intel/e1000e/mac.c')
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/mac.c | 11 |
1 files changed, 8 insertions, 3 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; } /** |