diff -ur linux-2.6.11/drivers/pci/Kconfig linux-2.6.11-new/drivers/pci/Kconfig
--- linux-2.6.11/drivers/pci/Kconfig	2005-03-01 23:37:51.000000000 -0800
+++ linux-2.6.11-new/drivers/pci/Kconfig	2005-04-01 07:19:32.000000000 -0800
@@ -47,3 +47,38 @@
 
 	  When in doubt, say Y.
 
+choice
+	prompt "Enable PCI Master Abort Mode"
+	depends on PCI
+	default PCI_MASTER_ABORT_DEFAULT
+	help
+	  On PCI systems, when a bus is unavailable to a bus master, a 
+	  master abort occurs.  Older bridges satisfy the master request
+	  with all 0xFF's.  This can lead to silent data corruption.  Newer
+	  bridges can send a target abort to the bus master.  Some PCI
+	  hardware cannot handle the target abort.  Some x86 BIOSes configure
+          the buses in a suboptimal way.  This option allows you to override
+	  the BIOS setting.  If unsure chose default.  This choice can be
+	  overridden at boot time with the pci_enable_master_abort={default,
+	  enable, disable}
+
+config PCI_MASTER_ABORT_DEFAULT
+	bool "Default"
+	help
+	  Choose this option if you are unsure, or believe your
+	  firmware does the right thing.
+
+config PCI_MASTER_ABORT_ENABLE
+	bool "Enable"
+	help
+	  Choose this option if it is more important for you to prevent
+	  silent data loss than to have more hardware configurations work.
+
+
+config PCI_MASTER_ABORT_DISABLE
+	bool "Disable"
+	help
+	  Choose this option if it is more important for you to have more
+	  hardware configurations work than to prevent silent data loss.
+
+endchoice
diff -ur linux-2.6.11/drivers/pci/probe.c linux-2.6.11-new/drivers/pci/probe.c
--- linux-2.6.11/drivers/pci/probe.c	2005-03-01 23:38:13.000000000 -0800
+++ linux-2.6.11-new/drivers/pci/probe.c	2005-04-05 12:07:53.000000000 -0700
@@ -28,6 +28,15 @@
 
 LIST_HEAD(pci_devices);
 
+/* used to force master abort mode on or off at runtime.
+   PCI_MASTER_ABORT_DEFAULT means leave alone, the BIOS got it correct.
+   PCI_MASTER_ABORT_ENABLE means turn it on everywhere.
+   PCI_MASTER_ABORT_DISABLE means turn it off everywhere.
+*/
+
+static int pci_enable_master_abort=PCI_MASTER_ABORT_VAL;
+
+
 #ifdef HAVE_PCI_LEGACY
 /**
  * pci_create_legacy_files - create legacy I/O port and memory files
@@ -429,6 +438,20 @@
 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
 			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
 
+	/* Some BIOSes disable master abort mode, even though it's
+	   usually a good thing (prevents silent data corruption).
+	   Unfortunately some hardware (buggy e-1000 chips for
+	   example) require Master Abort Mode to be off, or they will
+	   not function properly. So we enable master abort mode
+	   unless the user told us not to.  The default value
+	   for pci_enable_master_abort is set in the config file,
+	   but can be overridden at setup time. */
+	if (pci_enable_master_abort == PCI_MASTER_ABORT_ENABLE) {
+		bctl |= PCI_BRIDGE_CTL_MASTER_ABORT;
+	} else if (pci_enable_master_abort == PCI_MASTER_ABORT_DISABLE) {
+		bctl &= ~PCI_BRIDGE_CTL_MASTER_ABORT;
+	}
+
 	pci_enable_crs(dev);
 
 	if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) {
@@ -932,6 +955,22 @@
 	kfree(b);
 	return NULL;
 }
+
+static int __devinit pci_enable_master_abort_setup(char *str)
+{
+	if (strcmp(str, "enable") == 0) {
+		pci_enable_master_abort = PCI_MASTER_ABORT_ENABLE;
+	} else if (strcmp(str, "disable") == 0) {
+		pci_enable_master_abort = PCI_MASTER_ABORT_DISABLE;
+	} else if (strcmp(str, "default") == 0) {
+		pci_enable_master_abort = PCI_MASTER_ABORT_DEFAULT;
+	} else {
+		printk (KERN_ERR "PCI: Unknown Master Abort Mode (%s).", str);
+	}
+}
+
+__setup("pci_enable_master_abort=", pci_enable_master_abort_setup);
+
 EXPORT_SYMBOL(pci_scan_bus_parented);
 
 #ifdef CONFIG_HOTPLUG
diff -ur linux-2.6.11/include/linux/pci.h linux-2.6.11-new/include/linux/pci.h
--- linux-2.6.11/include/linux/pci.h	2005-03-01 23:38:08.000000000 -0800
+++ linux-2.6.11-new/include/linux/pci.h	2005-04-01 07:19:18.000000000 -0800
@@ -1064,5 +1064,17 @@
 #define PCIPCI_VSFX		16
 #define PCIPCI_ALIMAGIK		32
 
+#define PCI_MASTER_ABORT_DEFAULT	0
+#define PCI_MASTER_ABORT_ENABLE		1
+#define PCI_MASTER_ABORT_DISABLE	2
+
+#if defined(CONFIG_PCI_MASTER_ABORT_ENABLE)
+#   define PCI_MASTER_ABORT_VAL PCI_MASTER_ABORT_ENABLE
+#elif defined(CONFIG_PCI_MASTER_ABORT_DISABLE)
+#   define PCI_MASTER_ABORT_VAL PCI_MASTER_ABORT_DISABLE
+#else 
+#   define PCI_MASTER_ABORT_VAL PCI_MASTER_ABORT_DEFAULT
+#endif
+
 #endif /* __KERNEL__ */
 #endif /* LINUX_PCI_H */