Re: [PATCH 08/13] PCI: cadence: Use local management register to configure Vendor ID

From: Andrew Murray
Date: Tue Dec 17 2019 - 07:42:44 EST


On Mon, Dec 09, 2019 at 02:51:42PM +0530, Kishon Vijay Abraham I wrote:
> 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.

Is this a bug fix? Can you add a Fixes tag and make that clearer?

Thanks,

Andrew Murray

>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> ---
> drivers/pci/controller/cadence/pcie-cadence-host.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
> index cf817be237af..afb2c96a6538 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-host.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
> @@ -71,6 +71,7 @@ static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
> {
> struct cdns_pcie *pcie = &rc->pcie;
> u32 value, ctrl;
> + u32 id;
>
> /*
> * Set the root complex BAR configuration register:
> @@ -90,8 +91,12 @@ static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
> 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);
>
> --
> 2.17.1
>