Re: [PATCH v2 10/10] e1000e: Use pcie_capability_read_word() for reading LNKSTA

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Wed, 13 Sep 2023 15:27:48 +0300
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> wrote:

> Use pcie_capability_read_word() for reading LNKSTA and remove the
> custom define that matches to PCI_EXP_LNKSTA.
> 
> As only single user for cap_offset remains, remove it too and use
> adapter->pdev->pcie_cap directly in the if condition.
> 
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> ---
>  drivers/net/ethernet/intel/e1000e/defines.h |  1 -
>  drivers/net/ethernet/intel/e1000e/mac.c     | 10 ++++------
>  2 files changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h
> index a4d29c9e03a6..23a58cada43a 100644
> --- a/drivers/net/ethernet/intel/e1000e/defines.h
> +++ b/drivers/net/ethernet/intel/e1000e/defines.h
> @@ -678,7 +678,6 @@
>  
>  /* PCI/PCI-X/PCI-EX Config space */
>  #define PCI_HEADER_TYPE_REGISTER     0x0E
> -#define PCIE_LINK_STATUS             0x12
>  
>  #define PCI_HEADER_TYPE_MULTIFUNC    0x80
>  
> diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
> index 5340cf73778d..e86652a30069 100644
> --- a/drivers/net/ethernet/intel/e1000e/mac.c
> +++ b/drivers/net/ethernet/intel/e1000e/mac.c
> @@ -18,15 +18,13 @@ s32 e1000e_get_bus_info_pcie(struct e1000_hw *hw)
>  	struct e1000_mac_info *mac = &hw->mac;
>  	struct e1000_bus_info *bus = &hw->bus;
>  	struct e1000_adapter *adapter = hw->adapter;
> -	u16 pcie_link_status, cap_offset;
> +	u16 pcie_link_status;
>  
> -	cap_offset = adapter->pdev->pcie_cap;
> -	if (!cap_offset) {
> +	if (!adapter->pdev->pcie_cap) {

Could use pci_pcie_cap() though it'll end up longer, so not sure if it is
a good idea.
Given number of accesses to adapter->pdev, perhaps a local variable pdev, would help.

>  		bus->width = e1000_bus_width_unknown;
>  	} else {
> -		pci_read_config_word(adapter->pdev,
> -				     cap_offset + PCIE_LINK_STATUS,
> -				     &pcie_link_status);
> +		pcie_capability_read_word(adapter->pdev, PCI_EXP_LNKSTA,
> +					  &pcie_link_status);
>  		bus->width = (enum e1000_bus_width)FIELD_GET(PCI_EXP_LNKSTA_NLW,
>  							     pcie_link_status);
>  	}