dm: pci: Support bridge device configuration correctly

Commit aec241d "dm: pci: Use the correct hose when configuring devices"
was an attempt to fix pci bridge device configuration, but unfortunately
that does not work 100%. In pciauto_config_devices(), the fix tried to
call pciauto_config_device() with a ctlr_hose which is supposed to be
the root controller hose, however when walking through a pci topology
with 2 or more pci bridges this logic simply fails.

The call chain is: pciauto_config_devices()->pciauto_config_device()
->dm_pci_hose_probe_bus(). Here the call to dm_pci_hose_probe_bus()
does not make any sense as the given hose is not the bridge device's
hose, instead it is either the root controller's hose (case#1: if it
is the 2nd pci bridge), or the bridge's parent bridge's hose (case#2:
if it is the 3rd pci bridge). In both cases the logic is wrong.

For example, for failing case#1 if the bridge device to config has the
same devfn as one of the devices under the root controller, the call
to pci_bus_find_devfn() will return the udevice of that pci device
under the root controller as the bus, but this is wrong as the udevice
is not a bus which does not contain all the necessary bits associated
with the udevice which causes further failures.

To correctly support pci bridge device configuration, we should still
call pciauto_config_device() with the pci bridge's hose directly.
In order to access valid pci region information, we need to refer to
the root controller simply by a call to pci_bus_to_hose(0) and get the
region information there in the pciauto_prescan_setup_bridge(),
pciauto_postscan_setup_bridge() and pciauto_config_device().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/pci/pci_common.c b/drivers/pci/pci_common.c
index f67c9c7..07f1726 100644
--- a/drivers/pci/pci_common.c
+++ b/drivers/pci/pci_common.c
@@ -224,7 +224,7 @@ phys_addr_t pci_hose_bus_to_phys(struct pci_controller *hose,
 
 #ifdef CONFIG_DM_PCI
 	/* The root controller has the region information */
-	hose = hose->ctlr->uclass_priv;
+	hose = pci_bus_to_hose(0);
 #endif
 
 	/*
@@ -289,6 +289,11 @@ pci_addr_t pci_hose_phys_to_bus(struct pci_controller *hose,
 		return bus_addr;
 	}
 
+#ifdef CONFIG_DM_PCI
+	/* The root controller has the region information */
+	hose = pci_bus_to_hose(0);
+#endif
+
 	/*
 	 * if PCI_REGION_MEM is set we do a two pass search with preference
 	 * on matches that don't have PCI_REGION_SYS_MEMORY set