Re: [PATCH] PCI: altera: Retrain link in rootport mode only

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Aug 15, 2016 at 04:36:19PM +0800, Ley Foon Tan wrote:
> Altera PCIe IP can be configured as rootport or device and they might have
> same vendor ID. It will cause the system hang issue if Altera PCIe is in
> endpoint mode and work with other PCIe rootport that from other vendors.
> So, add the rootport mode checking in link retrain fixup function.
> 
> Signed-off-by: Ley Foon Tan <lftan@altera.com>
> ---
>  drivers/pci/host/pcie-altera.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c
> index 58eef99..6477738 100644
> --- a/drivers/pci/host/pcie-altera.c
> +++ b/drivers/pci/host/pcie-altera.c
> @@ -139,6 +139,9 @@ static void altera_pcie_retrain(struct pci_dev *dev)
>  	u16 linkcap, linkstat;
>  	struct altera_pcie *pcie = dev->bus->sysdata;
>  
> +	if (!pci_is_root_bus(dev->bus))
> +		return;

It seems like it would be more direct to check for
"pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT"?

>  	if (!altera_pcie_link_is_up(pcie))
>  		return;
>  
> -- 
> 1.8.2.1
>