[PATCH] PCI: cadence-plat: Fix host/endpoint dependencies

[Aksh Garg]

The cadence-plat driver has a single platform driver that can be built-in
or a loadable module, but it calls two separate backend drivers depending
on whether it is a host or endpoint.

If one of the mode is build as built-in and another as loadable module,
we end up with a situation where the built-in pcie-cadence-plat driver
tries to call the modular host or endpoint driver, which causes a link
failure:

  ld: error: undefined symbol: cdns_pcie_ep_setup
  >>> referenced by pcie-cadence-plat.c
  >>>               drivers/pci/controller/cadence/pcie-cadence-plat.o:(cdns_plat_pcie_probe) in archive vmlinux.a

  ld: error: undefined symbol: cdns_pcie_host_setup
  >>> referenced by pcie-cadence-plat.c
  >>>               drivers/pci/controller/cadence/pcie-cadence-plat.o:(cdns_plat_pcie_probe) in archive vmlinux.a

Fix this by moving the 'select' of PCIE_CADENCE_HOST and PCIE_CADENCE_EP
from the individual PLAT_HOST/PLAT_EP symbols into the common PCIE_CADENCE_PLAT
symbol, conditioned on which backends (modes) are enabled.

Fixes: 611627a4e5e4 ("PCI: cadence: Add module support for platform controller driver")
Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Closes: https://lore.kernel.org/linux-next/589ea512-93c6-4e1c-83d7-ba45a0b35843@xxxxxxxxxxxxx/
Signed-off-by: Aksh Garg <a-garg7@xxxxxx>
---
 drivers/pci/controller/cadence/Kconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
index 9e651d545973..fd704dec47dd 100644
--- a/drivers/pci/controller/cadence/Kconfig
+++ b/drivers/pci/controller/cadence/Kconfig
@@ -20,11 +20,12 @@ config PCIE_CADENCE_EP
 
 config PCIE_CADENCE_PLAT
 	tristate
+	select PCIE_CADENCE_HOST if PCIE_CADENCE_PLAT_HOST != n
+	select PCIE_CADENCE_EP if PCIE_CADENCE_PLAT_EP != n
 
 config PCIE_CADENCE_PLAT_HOST
 	tristate "Cadence platform PCIe controller (host mode)"
 	depends on OF
-	select PCIE_CADENCE_HOST
 	select PCIE_CADENCE_PLAT
 	help
 	  Say Y here if you want to support the Cadence PCIe platform controller in
@@ -35,7 +36,6 @@ config PCIE_CADENCE_PLAT_EP
 	tristate "Cadence platform PCIe controller (endpoint mode)"
 	depends on OF
 	depends on PCI_ENDPOINT
-	select PCIE_CADENCE_EP
 	select PCIE_CADENCE_PLAT
 	help
 	  Say Y here if you want to support the Cadence PCIe platform controller in
-- 
2.34.1