[PATCH] mmconfig: Reject a broken MCFG tables on Asus etc

This rejects broken MCFG tables on Asus. When the table
looks bogus just disable mmconfig

Arjan and Andi suggested this.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 23 insertions, 1 deletions

diff --git a/arch/i386/pci/mmconfig-shared.c b/arch/i386/pci/mmconfig-shared.c
index 4757554b08cf..77de6de94f1f 100644
--- a/arch/i386/pci/mmconfig-shared.c
+++ b/arch/i386/pci/mmconfig-shared.c
@@ -197,6 +197,26 @@ static __init void pci_mmcfg_insert_resources(void)
         }
 }
 
+static void __init pci_mmcfg_reject_broken(void)
+{
+        typeof(pci_mmcfg_config[0]) *cfg = &pci_mmcfg_config[0];
+
+        /*
+         * Handle more broken MCFG tables on Asus etc.
+         * They only contain a single entry for bus 0-0.
+         */
+        if (pci_mmcfg_config_num == 1 &&
+            cfg->pci_segment == 0 &&
+            (cfg->start_bus_number | cfg->end_bus_number) == 0) {
+                kfree(pci_mmcfg_config);
+                pci_mmcfg_config = NULL;
+                pci_mmcfg_config_num = 0;
+
+                printk(KERN_ERR "PCI: start and end of bus number is 0. "
+                       "Rejected as broken MCFG.");
+        }
+}
+
 void __init pci_mmcfg_init(int type)
 {
         int known_bridge = 0;
@@ -207,8 +227,10 @@ void __init pci_mmcfg_init(int type)
         if (type == 1 && pci_mmcfg_check_hostbridge())
                 known_bridge = 1;
 
-        if (!known_bridge)
+        if (!known_bridge) {
                 acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
+                pci_mmcfg_reject_broken();
+        }
 
         if ((pci_mmcfg_config_num == 0) ||
             (pci_mmcfg_config == NULL) ||