bge: For BCM5703, limit DMA read watermark

For BCM5703 in PCI-X mode, DMA read watermark should be less than
or equal to maximum read byte count configuration. Enforce this
limitation in DMA read watermark configuration.

Obtained-from: FreeBSD 204978

diff --git a/sys/dev/netif/bge/if_bge.c b/sys/dev/netif/bge/if_bge.c
index 48e8797..deeaf39 100644 (file)
--- a/sys/dev/netif/bge/if_bge.c
+++ b/sys/dev/netif/bge/if_bge.c
@@ -1259,6 +1259,16 @@ bge_chipinit(struct bge_softc *sc)
                        } else {
                                dma_rw_ctl |= (1 << 20) | (1 << 18) | (1 << 15);
                        }
+               } else if (sc->bge_asicrev == BGE_ASICREV_BCM5703) {
+                       /*
+                        * In the BCM5703, the DMA read watermark should
+                        * be set to less than or equal to the maximum
+                        * memory read byte count of the PCI-X command
+                        * register.
+                        */
+                       dma_rw_ctl = BGE_PCI_READ_CMD|BGE_PCI_WRITE_CMD |
+                           (0x4 << BGE_PCIDMARWCTL_RD_WAT_SHIFT) |
+                           (0x3 << BGE_PCIDMARWCTL_WR_WAT_SHIFT);
                } else if (sc->bge_asicrev == BGE_ASICREV_BCM5704) {
                        /*
                         * The 5704 uses a different encoding of read/write