[PATCH] PCI: designware: check for iATU unroll support after initializing host

From: Niklas Cassel
Date: Fri Oct 14 2016 - 17:56:37 EST


From: Niklas Cassel <niklas.cassel@xxxxxxxx>

dw_pcie_iatu_unroll_enabled reads a dbi_base register.
Reading any dbi_base register before pp->ops->host_init has been called
causes "imprecise external abort" on platforms like ARTPEC-6, where the
PCIe module is disabled at boot and first enabled in pp->ops->host_init.
Move dw_pcie_iatu_unroll_enabled to dw_pcie_setup_rc, since it is after
pp->ops->host_init, but before pp->iatu_unroll_enabled is actually used.

Fixes: a0601a470537 ("PCI: designware: Add iATU Unroll feature")
Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>
---
drivers/pci/host/pcie-designware.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 035f50c03281..bed19994c1e9 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -637,8 +637,6 @@ int dw_pcie_host_init(struct pcie_port *pp)
}
}

- pp->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pp);
-
if (pp->ops->host_init)
pp->ops->host_init(pp);

@@ -809,6 +807,11 @@ 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;
--
2.1.4