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

From: Joao Pinto
Date: Mon Oct 17 2016 - 10:34:55 EST



On 10/14/2016 10:54 PM, Niklas Cassel wrote:
> 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;
>

Acked-by: Joao Pinto <jpinto@xxxxxxxxxxxx>

Thanks
Joao