Re: [PATCH v2] PCI: xilinx-nwl: Remove unnecessary code which updates primary,secondary and sub-ordinate bus numbers.

[Bjorn Helgaas]

On Tue, Aug 08, 2023 at 04:07:30PM +0530, Thippeswamy Havalige wrote:
> The primary,secondary and sub-ordinate bus number registers are updated by
> Linux PCI core, so remove code which updates repective fields of type 1
> header 18th offset of Root Port configuration space.

Whoever applies this, please:

  - Drop period from subject line
  - Add space after comma
  - s/repective/respective/
  - Fix up "18th"; I suppose this refers to the 18h offset, but the
    reference is too low-level and probably unnecessary since we
    already listed the affected registers

> Signed-off-by: Thippeswamy Havalige <thippeswamy.havalige@xxxxxxx>
> Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xxxxxxx>
> ---
> changes in v2:
> - Code increasing ECAM Size value is added into a seperate patch.
> - Modified commit messages.
> changes in v1:
> - Modified commit messages.
> ---
>  drivers/pci/controller/pcie-xilinx-nwl.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c
> index 176686b..a73554e 100644
> --- a/drivers/pci/controller/pcie-xilinx-nwl.c
> +++ b/drivers/pci/controller/pcie-xilinx-nwl.c
> @@ -165,8 +165,6 @@ struct nwl_pcie {
>  	u32 ecam_size;
>  	int irq_intx;
>  	int irq_misc;
> -	u32 ecam_value;

The removal of "ecam_value" has nothing to do with the PCI core; it
seems more related to the NWL_ECAM_VALUE_DEFAULT change, and I would
either squash it into that patch or make it a separate "no functional
change" cleanup patch.

> -	u8 last_busno;
>  	struct nwl_msi msi;
>  	struct irq_domain *legacy_irq_domain;
>  	struct clk *clk;
> @@ -625,7 +623,7 @@ static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
>  {
>  	struct device *dev = pcie->dev;
>  	struct platform_device *pdev = to_platform_device(dev);
> -	u32 breg_val, ecam_val, first_busno = 0;
> +	u32 breg_val, ecam_val;
>  	int err;
>  
>  	breg_val = nwl_bridge_readl(pcie, E_BREG_CAPABILITIES) & BREG_PRESENT;
> @@ -675,7 +673,7 @@ static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
>  			  E_ECAM_CR_ENABLE, E_ECAM_CONTROL);
>  
>  	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
> -			  (pcie->ecam_value << E_ECAM_SIZE_SHIFT),
> +			  (NWL_ECAM_VALUE_DEFAULT << E_ECAM_SIZE_SHIFT),
>  			  E_ECAM_CONTROL);
>  
>  	nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_ecam_base),
> @@ -683,15 +681,6 @@ static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
>  	nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_ecam_base),
>  			  E_ECAM_BASE_HI);
>  
> -	/* Get bus range */
> -	ecam_val = nwl_bridge_readl(pcie, E_ECAM_CONTROL);
> -	pcie->last_busno = (ecam_val & E_ECAM_SIZE_LOC) >> E_ECAM_SIZE_SHIFT;
> -	/* Write primary, secondary and subordinate bus numbers */
> -	ecam_val = first_busno;
> -	ecam_val |= (first_busno + 1) << 8;
> -	ecam_val |= (pcie->last_busno << E_ECAM_SIZE_SHIFT);
> -	writel(ecam_val, (pcie->ecam_base + PCI_PRIMARY_BUS));
> -
>  	if (nwl_pcie_link_up(pcie))
>  		dev_info(dev, "Link is UP\n");
>  	else
> @@ -792,7 +781,6 @@ static int nwl_pcie_probe(struct platform_device *pdev)
>  	pcie = pci_host_bridge_priv(bridge);
>  
>  	pcie->dev = dev;
> -	pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;
>  
>  	err = nwl_pcie_parse_dt(pcie, pdev);
>  	if (err) {
> -- 
> 1.8.3.1
> 
> 
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