From: Kishon Vijay Abraham I <kishon@ti.com>
Date: Wed, 22 Jul 2020 16:33:11 +0530
Subject: PCI: cadence: Fix updating Vendor ID and Subsystem Vendor ID register
Git-commit: e3bca37d15dca118f2ef1f0a068bb6e07846ea20
Patch-mainline: v5.9-rc1
References: git-fixes

Commit 1b79c5284439 ("PCI: cadence: Add host driver for Cadence PCIe
controller") in order to update Vendor ID, directly wrote to
PCI_VENDOR_ID register. However PCI_VENDOR_ID in root port configuration
space is read-only register and writing to it will have no effect.
Use local management register to configure Vendor ID and Subsystem Vendor
ID.

Link: https://lore.kernel.org/r/20200722110317.4744-10-kishon@ti.com
Fixes: 1b79c5284439 ("PCI: cadence: Add host driver for Cadence PCIe controller")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/pci/controller/pcie-cadence-host.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/pci/controller/pcie-cadence-host.c
+++ b/drivers/pci/controller/pcie-cadence-host.c
@@ -102,6 +102,7 @@ static int cdns_pcie_host_init_root_port
 {
 	struct cdns_pcie *pcie = &rc->pcie;
 	u32 value, ctrl;
+	u32 id;
 
 	/*
 	 * Set the root complex BAR configuration register:
@@ -121,8 +122,12 @@ static int cdns_pcie_host_init_root_port
 	cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
 
 	/* Set root port configuration space */
-	if (rc->vendor_id != 0xffff)
-		cdns_pcie_rp_writew(pcie, PCI_VENDOR_ID, rc->vendor_id);
+	if (rc->vendor_id != 0xffff) {
+		id = CDNS_PCIE_LM_ID_VENDOR(rc->vendor_id) |
+			CDNS_PCIE_LM_ID_SUBSYS(rc->vendor_id);
+		cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
+	}
+
 	if (rc->device_id != 0xffff)
 		cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, rc->device_id);