svn commit: r222142 - head/sys/dev/vge

[Pyun YongHyeon]

Author: yongari
Date: Fri May 20 18:27:13 2011
New Revision: 222142
URL: http://svn.freebsd.org/changeset/base/222142

Log:
  Datasheet says vge(4) controllers support DAC but it seems that's
  not true on old PCI based controllers.  DAC configuration is read
  from EEPROM in device reset phase and driver can override DAC
  configuration.  However I guess there is an undocumented reason why
  EEPROM configuration does not enable DAC so do not blindly override
  DAC configuration.  Recent PCIe based controllers are supposed to
  support 64bit DMA so allow 64bit DMA only on PCIe based controllers.
  
  PR:		kern/157184
  MFC after:	1 week

Modified:
  head/sys/dev/vge/if_vge.c

Modified: head/sys/dev/vge/if_vge.c
==============================================================================
--- head/sys/dev/vge/if_vge.c	Fri May 20 17:43:38 2011	(r222141)
+++ head/sys/dev/vge/if_vge.c	Fri May 20 18:27:13 2011	(r222142)
@@ -685,7 +685,18 @@ vge_dma_alloc(struct vge_softc *sc)
 	bus_addr_t lowaddr, tx_ring_end, rx_ring_end;
 	int error, i;
 
-	lowaddr = BUS_SPACE_MAXADDR;
+	/*
+	 * It seems old PCI controllers do not support DAC.  DAC
+	 * configuration can be enabled by accessing VGE_CHIPCFG3
+	 * register but honor EEPROM configuration instead of
+	 * blindly overriding DAC configuration.  PCIe based
+	 * controllers are supposed to support 64bit DMA so enable
+	 * 64bit DMA on these controllers.
+	 */
+	if ((sc->vge_flags & VGE_FLAG_PCIE) != 0)
+		lowaddr = BUS_SPACE_MAXADDR;
+	else
+		lowaddr = BUS_SPACE_MAXADDR_32BIT;
 
 again:
 	/* Create parent ring tag. */
@@ -802,10 +813,14 @@ again:
 		goto again;
 	}
 
+	if ((sc->vge_flags & VGE_FLAG_PCIE) != 0)
+		lowaddr = VGE_BUF_DMA_MAXADDR;
+	else
+		lowaddr = BUS_SPACE_MAXADDR_32BIT;
 	/* Create parent buffer tag. */
 	error = bus_dma_tag_create(bus_get_dma_tag(sc->vge_dev),/* parent */
 	    1, 0,			/* algnmnt, boundary */
-	    VGE_BUF_DMA_MAXADDR,	/* lowaddr */
+	    lowaddr,			/* lowaddr */
 	    BUS_SPACE_MAXADDR,		/* highaddr */
 	    NULL, NULL,			/* filter, filterarg */
 	    BUS_SPACE_MAXSIZE_32BIT,	/* maxsize */