Re: [PATCH 2/2] PCI: amd-mdb: Add amd,versal2-cpm6-host compatible

[Manivannan Sadhasivam]

On Thu, Apr 02, 2026 at 11:30:06PM +0530, Sai Krishna Musham wrote:
> Add "amd,versal2-cpm6-host" to the OF match table of the AMD MDB PCIe
> host controller driver.
> 
> The Versal2 CPM6 host controller is DesignWare-based and supports
> PCIe Gen6 operation at up to 64 GT/s per lane. It is currently
> handled by the same driver and match data (NULL) as the existing
> MDB host controller, but CPM6 uses a newer IP revision and differs
> in legacy INTx register offsets.
> 
> Use a separate compatible to allow CPM6-specific handling once legacy
> interrupt support is validated.
> 
> Signed-off-by: Sai Krishna Musham <sai.krishna.musham@xxxxxxx>
> ---
>  drivers/pci/controller/dwc/pcie-amd-mdb.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> index 3c6e837465bb..325bf7aad657 100644
> --- a/drivers/pci/controller/dwc/pcie-amd-mdb.c
> +++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> @@ -511,6 +511,9 @@ static const struct of_device_id amd_mdb_pcie_of_match[] = {
>  	{
>  		.compatible = "amd,versal2-mdb-host",
>  	},
> +	{
> +		.compatible = "amd,versal2-cpm6-host",

As Krzysztof commented, if the PCIe IP is compatible with an older version,
'amd,versal2-mdb-host' in this case, you don't need to add the new compatible
to the driver. Just document the new one with fallback to the old compatible in
the binding and let the driver work with the old compatible.

- Mani

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