[PATCH] PCI: designware: fix asynchronous external abort in keystone PCIe h/w

[Murali Karicheri <m-karicheri2@ti.com>]

Recent fixes for iATU unroll support introduced a bug that causes
asynchronous external abort in Keystone PCIe h/w which doesn't have
ATU port and the corresponding register. So the check should be moved
below where dw_pcie_prog_outbound_atu() is called to avoid that
being called on keystine PCIe h/w.

Here is the backtrace

[    0.771174] OF: PCI:   MEM 0x60000000..0x6fffffff -> 0x60000000
[    0.778118] Unhandled fault: asynchronous external abort (0x1211) at 0x00000000
[    0.785548] pgd = c0003000
[    0.788347] [00000000] *pgd=80000800004003, *pmd=00000000
[    0.793864] Internal error: : 1211 [#1] PREEMPT SMP ARM
[    0.799197] Modules linked in:
[    0.802351] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-00009-g6ff59d2-dirty #7
[    0.810130] Hardware name: Keystone
[    0.813717] task: eb878000 task.stack: eb866000
[    0.818356] PC is at dw_pcie_setup_rc+0x24/0x380
[    0.823083] LR is at ks_pcie_host_init+0x10/0x170

Fixes: 416379f9ebde ("PCI: designware: Check for iATU unroll support after initializing host")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Tested-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 - Applies to pci/master
 - Bug was introduced in v4.9
 - Tested on K2E EVM with SATA and DRA7-EVM with an intel PCI ethernet card

 drivers/pci/host/pcie-designware.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index bed1999..af8f6e9 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -807,11 +807,6 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 {
 	u32 val;
 
-	/* get iATU unroll support */
-	pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
-	dev_dbg(pp->dev, "iATU unroll: %s\n",
-		pp->iatu_unroll_enabled ? "enabled" : "disabled");
-
 	/* set the number of lanes */
 	val = dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL);
 	val &= ~PORT_LINK_MODE_MASK;
@@ -882,6 +877,11 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 	 * we should not program the ATU here.
 	 */
 	if (!pp->ops->rd_other_conf) {
+		/* get iATU unroll support */
+		pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
+		dev_dbg(pp->dev, "iATU unroll: %s\n",
+			pp->iatu_unroll_enabled ? "enabled" : "disabled");
+
 		dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
 					  PCIE_ATU_TYPE_MEM, pp->mem_base,
 					  pp->mem_bus_addr, pp->mem_size);
-- 
1.9.1