Re: [PATCH v4 2/5] PCI: designware-ep: Make dw_pcie_ep_set_bar() handle 64-bit BARs properly

[Kishon Vijay Abraham I]

Hi Niklas,

On Thursday 08 March 2018 07:03 PM, Niklas Cassel wrote:
> Since a 64-bit BAR consists of a BAR pair, we need to write to both
> BARs in the BAR pair to setup the BAR properly.
> 
> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>
> ---
>  drivers/pci/dwc/pcie-designware-ep.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index 9236b998327f..946bbdf53c4d 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -136,8 +136,15 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
>  		return ret;
>  
>  	dw_pcie_dbi_ro_wr_en(pci);
> -	dw_pcie_writel_dbi2(pci, reg, size - 1);
> -	dw_pcie_writel_dbi(pci, reg, flags);
> +	if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) {
> +		dw_pcie_writel_dbi2(pci, reg, lower_32_bits(size - 1));
> +		dw_pcie_writel_dbi(pci, reg, flags);
> +		dw_pcie_writel_dbi2(pci, reg + 4, upper_32_bits(size - 1));
> +		dw_pcie_writel_dbi(pci, reg + 4, 0);

I think we should check in pci_epc_set_bar to make sure BAR_5 cannot have
PCI_BASE_ADDRESS_MEM_TYPE_64 flag set as this might lead undesired result.

Thanks
Kishon