[PATCH] DDX/PCI: Check harder for primary PCI device

[Egbert Eich]

Primary PCI devices are identified by checking for an 'PCIINFOCLASSES'
device which is VGA and has access to the memory bars enabled.
If there should be more than one device for which this is true
redo the check and also check if IO resoures are also enabled,
if this still doesn't turn up a unique result also check for
the presence of a BIOS rom.

Signed-off-by: Egbert Eich <eich at freedesktop.org>
---
 hw/xfree86/common/xf86pciBus.c | 47 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/hw/xfree86/common/xf86pciBus.c b/hw/xfree86/common/xf86pciBus.c
index 258988a..2303f90 100644
--- a/hw/xfree86/common/xf86pciBus.c
+++ b/hw/xfree86/common/xf86pciBus.c
@@ -134,9 +134,50 @@ xf86PciProbe(void)
                     primaryBus.id.pci = info;
                 }
                 else {
-                    xf86Msg(X_NOTICE,
-                            "More than one possible primary device found\n");
-                    primaryBus.type ^= (BusType) (-1);
+                    /*
+                     * Ok, we found more than one possible primary device
+                     * with this heuristic. Now also check if IO is enabled.
+                     */
+                    int j;
+
+                    primaryBus.type = BUS_NONE;
+                    for (j = 0; j < num; j++) {
+                        info = xf86PciVideoInfo[j];
+                        pci_device_cfg_read_u16(info, & command, 4);
+
+                        if ((command & PCI_CMD_MEM_ENABLE)
+                            && (command & PCI_CMD_IO_ENABLE)
+                            && (IS_VGA(info->device_class))) {
+                            if (primaryBus.type == BUS_NONE) {
+                                primaryBus.type = BUS_PCI;
+                                primaryBus.id.pci = info;
+                            } else {
+                                primaryBus.type = BUS_NONE;
+                                for (j = 0; j < num; j++) {
+                                    info = xf86PciVideoInfo[j];
+                                    pci_device_cfg_read_u16(info, &command, 4);
+
+                                    if ((command & PCI_CMD_MEM_ENABLE)
+                                        && (command & PCI_CMD_IO_ENABLE)
+                                        && (IS_VGA(info->device_class))
+                                        && info->rom_size) {
+                                        if (primaryBus.type == BUS_NONE) {
+                                            primaryBus.type = BUS_PCI;
+                                            primaryBus.id.pci = info;
+                                        } else {
+                                            xf86Msg(X_NOTICE,
+                                                    "More than one possible "
+                                                    "primary device found\n");
+                                            primaryBus.type ^= (BusType)(-1);
+                                            break;
+                                        }
+                                    }
+                                }
+                                break;
+                            }
+                        }
+                    }
+                    break;
                 }
             }
         }
-- 
1.8.1.4