tg3: Workaround rx_discards stat bug
The 5717, 5718, 5719 A0, and 5720 A0 has a bug where the rx_discards
statistic counter will increment when dropping unwanted multicast
frames. This patch works around the problem by attempting to
recreate the data using other means. The resulting value will not be
accurate, but it can still serve as a problem indicator.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 9915734..58787ea 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -339,6 +339,7 @@
{ "dma_write_prioq_full" },
{ "rxbds_empty" },
{ "rx_discards" },
+ { "mbuf_lwm_thresh_hit" },
{ "rx_errors" },
{ "rx_threshold_hit" },
@@ -8207,6 +8208,10 @@
val = BUFMGR_MODE_ENABLE | BUFMGR_MODE_ATTN_ENABLE;
if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719)
val |= BUFMGR_MODE_NO_TX_UNDERRUN;
+ if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717 ||
+ tp->pci_chip_rev_id == CHIPREV_ID_5719_A0 ||
+ tp->pci_chip_rev_id == CHIPREV_ID_5720_A0)
+ val |= BUFMGR_MODE_MBLOW_ATTN_ENAB;
tw32(BUFMGR_MODE, val);
for (i = 0; i < 2000; i++) {
if (tr32(BUFMGR_MODE) & BUFMGR_MODE_ENABLE)
@@ -8870,7 +8875,19 @@
TG3_STAT_ADD32(&sp->rx_undersize_packets, MAC_RX_STATS_UNDERSIZE);
TG3_STAT_ADD32(&sp->rxbds_empty, RCVLPC_NO_RCV_BD_CNT);
- TG3_STAT_ADD32(&sp->rx_discards, RCVLPC_IN_DISCARDS_CNT);
+ if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5717) {
+ TG3_STAT_ADD32(&sp->rx_discards, RCVLPC_IN_DISCARDS_CNT);
+ } else {
+ u32 val = tr32(HOSTCC_FLOW_ATTN);
+ val = (val & HOSTCC_FLOW_ATTN_MBUF_LWM) ? 1 : 0;
+ if (val) {
+ tw32(HOSTCC_FLOW_ATTN, HOSTCC_FLOW_ATTN_MBUF_LWM);
+ sp->rx_discards.low += val;
+ if (sp->rx_discards.low < val)
+ sp->rx_discards.high += 1;
+ }
+ sp->mbuf_lwm_thresh_hit = sp->rx_discards;
+ }
TG3_STAT_ADD32(&sp->rx_errors, RCVLPC_IN_ERRORS_CNT);
}
@@ -13973,6 +13990,14 @@
GET_CHIP_REV(tp->pci_chip_rev_id) != CHIPREV_5700_BX)
tp->coalesce_mode |= HOSTCC_MODE_32BYTE;
+ /* Set these bits to enable statistics workaround. */
+ if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717 ||
+ tp->pci_chip_rev_id == CHIPREV_ID_5719_A0 ||
+ tp->pci_chip_rev_id == CHIPREV_ID_5720_A0) {
+ tp->coalesce_mode |= HOSTCC_MODE_ATTN;
+ tp->grc_mode |= GRC_MODE_IRQ_ON_FLOW_ATTN;
+ }
+
if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5785 ||
GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_57780)
tp->tg3_flags3 |= TG3_FLG3_USE_PHYLIB;