igb: Prevent dropped Tx timestamps via work items and interrupts.

In rare circumstances, it's possible a descriptor writeback will occur
before a timestamped Tx packet will go out on the wire, leading to the
driver believing the hardware failed to timestamp the packet. Schedule a
work item for 82576 and use the available time sync interrupt registers
on 82580 and above to account for this.

Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/igb/e1000_defines.h b/drivers/net/ethernet/intel/igb/e1000_defines.h
index ec7e4fe3e3ee..0b27e8fe06bf 100644
--- a/drivers/net/ethernet/intel/igb/e1000_defines.h
+++ b/drivers/net/ethernet/intel/igb/e1000_defines.h
@@ -360,6 +360,7 @@
 #define E1000_ICR_RXDMT0        0x00000010 /* rx desc min. threshold (0) */
 #define E1000_ICR_RXT0          0x00000080 /* rx timer intr (ring 0) */
 #define E1000_ICR_VMMB          0x00000100 /* VM MB event */
+#define E1000_ICR_TS            0x00080000 /* Time Sync Interrupt */
 #define E1000_ICR_DRSTA         0x40000000 /* Device Reset Asserted */
 /* If this bit asserted, the driver should claim the interrupt */
 #define E1000_ICR_INT_ASSERTED  0x80000000
@@ -399,6 +400,7 @@
 #define E1000_IMS_TXDW      E1000_ICR_TXDW      /* Transmit desc written back */
 #define E1000_IMS_LSC       E1000_ICR_LSC       /* Link Status Change */
 #define E1000_IMS_VMMB      E1000_ICR_VMMB      /* Mail box activity */
+#define E1000_IMS_TS        E1000_ICR_TS        /* Time Sync Interrupt */
 #define E1000_IMS_RXSEQ     E1000_ICR_RXSEQ     /* rx sequence error */
 #define E1000_IMS_RXDMT0    E1000_ICR_RXDMT0    /* rx desc min. threshold */
 #define E1000_IMS_RXT0      E1000_ICR_RXT0      /* rx timer intr */
@@ -510,6 +512,9 @@
 
 #define E1000_TIMINCA_16NS_SHIFT 24
 
+#define E1000_TSICR_TXTS 0x00000002
+#define E1000_TSIM_TXTS 0x00000002
+
 #define E1000_MDICNFG_EXT_MDIO    0x80000000      /* MDI ext/int destination */
 #define E1000_MDICNFG_COM_MDIO    0x40000000      /* MDI shared w/ lan 0 */
 #define E1000_MDICNFG_PHY_MASK    0x03E00000