Most recent kernel where this bug did not occur: none
Distribution: ArchLinux
Hardware Environment: Asus M2V Socket AM2 Motherboard
Software Environment: Linux
Problem Description: The kernel does not properly detect my south bridge PCI
chipset, a VIA VT8237a. Because of this there is no way to enable DMA. There is
a simple fix, which is to update the via_isa_bridges structure table in
via82cxxx.c. Here is a patch:

--- linux-2.6.17/drivers/ide/pci/via82cxxx.c.old   2006-07-22 14:58:30.000000000
-0700
+++ linux-2.6.17/drivers/ide/pci/via82cxxx.c 2006-07-22 15:00:56.000000000 -0700
@@ -82,6 +82,7 @@
   { "vt6410", PCI_DEVICE_ID_VIA_6410,     0x00, 0x2f, VIA_UDMA_133 | VIA_BAD_AST },
   { "vt8251", PCI_DEVICE_ID_VIA_8251,     0x00, 0x2f, VIA_UDMA_133 | VIA_BAD_AST },
   { "vt8237", PCI_DEVICE_ID_VIA_8237,     0x00, 0x2f, VIA_UDMA_133 | VIA_BAD_AST },
+  { "vt8237a",PCI_DEVICE_ID_VIA_8237A,    0x00, 0x2f, VIA_UDMA_133 | VIA_BAD_AST },
   { "vt8235", PCI_DEVICE_ID_VIA_8235,     0x00, 0x2f, VIA_UDMA_133 | VIA_BAD_AST },
   { "vt8233a",   PCI_DEVICE_ID_VIA_8233A,    0x00, 0x2f, VIA_UDMA_133 |
VIA_BAD_AST },
   { "vt8233c",   PCI_DEVICE_ID_VIA_8233C_0,  0x00, 0x2f, VIA_UDMA_100 },

------------------

Also, pci_ids.h must be updated. Here is a patch:

--- linux-2.6.17/include/linux/pci_ids.h.old 2006-07-22 15:01:49.000000000 -0700
+++ linux-2.6.17/include/linux/pci_ids.h  2006-07-22 15:02:58.000000000 -0700
@@ -1281,6 +1281,7 @@
 #define PCI_DEVICE_ID_VIA_8378_0   0x3205
 #define PCI_DEVICE_ID_VIA_8783_0   0x3208
 #define PCI_DEVICE_ID_VIA_8237     0x3227
+#define PCI_DEVICE_ID_VIA_8237A    0x3337
 #define PCI_DEVICE_ID_VIA_8251     0x3287
 #define PCI_DEVICE_ID_VIA_3296_0   0x0296
 #define PCI_DEVICE_ID_VIA_8231     0x8231

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