[TG3]: Add rx BD workaround
Add workaround to limit the burst size of rx BDs being DMA'ed to the
chip. This works around hardware errata on a number of 5750, 5752,
and 5755 chips.
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 2447fa3..c32655c 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -3195,7 +3195,7 @@
*/
static int tg3_rx(struct tg3 *tp, int budget)
{
- u32 work_mask;
+ u32 work_mask, rx_std_posted = 0;
u32 sw_idx = tp->rx_rcb_ptr;
u16 hw_idx;
int received;
@@ -3222,6 +3222,7 @@
mapping);
skb = tp->rx_std_buffers[desc_idx].skb;
post_ptr = &tp->rx_std_ptr;
+ rx_std_posted++;
} else if (opaque_key == RXD_OPAQUE_RING_JUMBO) {
dma_addr = pci_unmap_addr(&tp->rx_jumbo_buffers[desc_idx],
mapping);
@@ -3309,6 +3310,15 @@
next_pkt:
(*post_ptr)++;
+
+ if (unlikely(rx_std_posted >= tp->rx_std_max_post)) {
+ u32 idx = *post_ptr % TG3_RX_RING_SIZE;
+
+ tw32_rx_mbox(MAILBOX_RCV_STD_PROD_IDX +
+ TG3_64BIT_REG_LOW, idx);
+ work_mask &= ~RXD_OPAQUE_RING_STD;
+ rx_std_posted = 0;
+ }
next_pkt_nopost:
sw_idx++;
sw_idx %= TG3_RX_RCB_RING_SIZE(tp);
@@ -5981,7 +5991,13 @@
}
/* Setup replenish threshold. */
- tw32(RCVBDI_STD_THRESH, tp->rx_pending / 8);
+ val = tp->rx_pending / 8;
+ if (val == 0)
+ val = 1;
+ else if (val > tp->rx_std_max_post)
+ val = tp->rx_std_max_post;
+
+ tw32(RCVBDI_STD_THRESH, val);
/* Initialize TG3_BDINFO's at:
* RCVDBDI_STD_BD: standard eth size rx ring
@@ -10545,6 +10561,16 @@
(tp->tg3_flags & TG3_FLAG_PCIX_MODE) != 0)
tp->rx_offset = 0;
+ tp->rx_std_max_post = TG3_RX_RING_SIZE;
+
+ /* Increment the rx prod index on the rx std ring by at most
+ * 8 for these chips to workaround hw errata.
+ */
+ if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5750 ||
+ GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5752 ||
+ GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5755)
+ tp->rx_std_max_post = 8;
+
/* By default, disable wake-on-lan. User can change this
* using ETHTOOL_SWOL.
*/