From b4ecb0509254e2b306a41e807ff92d977cf61a02 Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Mon, 2 Jul 2012 09:49:15 +0800
Subject: [PATCH] bge: Enable fix for read DMA FIFO overruns on certain
 controllers

Obtained-from: FreeBSD 213411
---
 sys/dev/netif/bge/if_bge.c    | 14 ++++++++++++++
 sys/dev/netif/bge/if_bgereg.h |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/sys/dev/netif/bge/if_bge.c b/sys/dev/netif/bge/if_bge.c
index 8b2f787a7b..452e45fd8c 100644
--- a/sys/dev/netif/bge/if_bge.c
+++ b/sys/dev/netif/bge/if_bge.c
@@ -1696,6 +1696,20 @@ bge_blockinit(struct bge_softc *sc)
 	CSR_WRITE_4(sc, BGE_WDMA_MODE, val);
 	DELAY(40);
 
+	if (sc->bge_asicrev == BGE_ASICREV_BCM5761 ||
+	    sc->bge_asicrev == BGE_ASICREV_BCM5784 ||
+	    sc->bge_asicrev == BGE_ASICREV_BCM5785 ||
+	    sc->bge_asicrev == BGE_ASICREV_BCM57780) {
+		/*
+		 * Enable fix for read DMA FIFO overruns.
+		 * The fix is to limit the number of RX BDs
+		 * the hardware would fetch at a fime.
+		 */
+		val = CSR_READ_4(sc, BGE_RDMA_RSRVCTRL);
+		CSR_WRITE_4(sc, BGE_RDMA_RSRVCTRL,
+		    val| BGE_RDMA_RSRVCTRL_FIFO_OFLW_FIX);
+	}
+
 	/* Turn on read DMA state machine */
 	val = BGE_RDMAMODE_ENABLE | BGE_RDMAMODE_ALL_ATTNS;
         if (sc->bge_asicrev == BGE_ASICREV_BCM5784 ||
diff --git a/sys/dev/netif/bge/if_bgereg.h b/sys/dev/netif/bge/if_bgereg.h
index 86d5890c02..ec4c5d24c3 100644
--- a/sys/dev/netif/bge/if_bgereg.h
+++ b/sys/dev/netif/bge/if_bgereg.h
@@ -1360,6 +1360,7 @@
  */
 #define BGE_RDMA_MODE			0x4800
 #define BGE_RDMA_STATUS			0x4804
+#define BGE_RDMA_RSRVCTRL		0x4900
 
 /* Read DMA mode register */
 #define BGE_RDMAMODE_RESET		0x00000001
@@ -1389,6 +1390,9 @@
 #define BGE_RDMASTAT_PCI_FIFOOREAD_ATTN	0x00000100
 #define BGE_RDMASTAT_LOCWRITE_TOOBIG	0x00000200
 
+/* Read DMA Reserved Control register */
+#define BGE_RDMA_RSRVCTRL_FIFO_OFLW_FIX	0x00000004
+
 /*
  * Write DMA control registers
  */
-- 
2.41.0