e1000e: Guarantee descriptor writeback flush success.

In rare circumstances, a descriptor writeback flush may not work if it
arrives on a specific clock cycle as a writeback request is going out.

Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Matthew Vick 2012-03-16 09:03:00 +00:00 committed by Jeff Kirsher
parent bb9e44d0d0
commit bf03085f85

View file

@ -1059,6 +1059,13 @@ static void e1000_print_hw_hang(struct work_struct *work)
ew32(TIDV, adapter->tx_int_delay | E1000_TIDV_FPD);
/* execute the writes immediately */
e1e_flush();
/*
* Due to rare timing issues, write to TIDV again to ensure
* the write is successful
*/
ew32(TIDV, adapter->tx_int_delay | E1000_TIDV_FPD);
/* execute the writes immediately */
e1e_flush();
adapter->tx_hang_recheck = true;
return;
}
@ -3616,6 +3623,16 @@ static void e1000e_flush_descriptors(struct e1000_adapter *adapter)
/* execute the writes immediately */
e1e_flush();
/*
* due to rare timing issues, write to TIDV/RDTR again to ensure the
* write is successful
*/
ew32(TIDV, adapter->tx_int_delay | E1000_TIDV_FPD);
ew32(RDTR, adapter->rx_int_delay | E1000_RDTR_FPD);
/* execute the writes immediately */
e1e_flush();
}
static void e1000e_update_stats(struct e1000_adapter *adapter);