On LS2K/LS7A, some unexisting devices don't return 0xffffffff when
scanning. This is a hardware flaw but we can only avoid it by software
now.
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
drivers/pci/controller/pci-loongson.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/pci-loongson.c b/drivers/pci/controller/pci-loongson.c
index adbfa4a2330f..48316daa1f23 100644
--- a/drivers/pci/controller/pci-loongson.c
+++ b/drivers/pci/controller/pci-loongson.c
@@ -138,6 +138,8 @@ static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devf
int where)
{
unsigned char busnum = bus->number;
+ unsigned int device = PCI_SLOT(devfn);
+ unsigned int function = PCI_FUNC(devfn);
struct loongson_pci *priv = pci_bus_to_loongson_pci(bus);
if (pci_is_root_bus(bus))
@@ -147,8 +149,13 @@ static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devf
* Do not read more than one device on the bus other than
* the host bus. For our hardware the root bus is always bus 0.
*/
- if (priv->data->flags & FLAG_DEV_FIX &&
- !pci_is_root_bus(bus) && PCI_SLOT(devfn) > 0)
+ if ((priv->data->flags & FLAG_DEV_FIX) && bus->self) {
+ if (!pci_is_root_bus(bus) && (device > 0))
+ return NULL;
+ }
+
+ /* Don't access unexisting devices */
+ if (pci_is_root_bus(bus) && (device >= 9 && device <= 20 && function > 0))
return NULL;
/* CFG0 can only access standard space */
--
2.27.0
