[PATCH] PCI: handle bogus MCFG entries

Handle more bogus MCFG entries

Some Asus P4 boards seem to have broken MCFG tables with
only a single entry for busses 0-0.  Special case these
and assume they mean all busses can be accessed.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 2 deletions

diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
index 4bb4d4b0f73a..0ee8a983708c 100644
--- a/arch/i386/pci/mmconfig.c
+++ b/arch/i386/pci/mmconfig.c
@@ -36,8 +36,7 @@ static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
         while (1) {
                 ++cfg_num;
                 if (cfg_num >= pci_mmcfg_config_num) {
-                        /* Not found - fallback to type 1 */
-                        return 0;
+                        break;
                 }
                 cfg = &pci_mmcfg_config[cfg_num];
                 if (cfg->pci_segment_group_number != seg)
@@ -46,6 +45,18 @@ static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
                     (cfg->end_bus_number >= bus))
                         return cfg->base_address;
         }
+
+        /* Handle more broken MCFG tables on Asus etc.
+           They only contain a single entry for bus 0-0. Assume
+           this applies to all busses. */
+        cfg = &pci_mmcfg_config[0];
+        if (pci_mmcfg_config_num == 1 &&
+                cfg->pci_segment_group_number == 0 &&
+                (cfg->start_bus_number | cfg->end_bus_number) == 0)
+                return cfg->base_address;
+
+        /* Fall back to type 0 */
+        return 0;
 }
 
 static inline void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)