Re: [PATCH 2/2] PCI: ultrarisc: Remove bypass_ob_mem_iatu variable on DP1000

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] PCI: ultrarisc: removing bypass_ob_mem_iatu after struct field breaks bisect
--

commit 64e39828c5cda3565ca7342abcafed6f323d27d1
Author: Xincheng Ji <jixincheng@ultrarisc.com>

PCI: ultrarisc: Remove bypass_ob_mem_iatu variable on DP1000

This commit removes the assignment to pp->bypass_ob_mem_iatu in
ultrarisc_pcie_probe() now that the DWC core handles identity-mapped MEM
outbound iATU bypass directly.

> diff --git a/drivers/pci/controller/dwc/pcie-ultrarisc.c b/drivers/pci/controller/dwc/pcie-ultrarisc.c
> index 523f454c6c524..a0d328c0c09b7 100644
> --- a/drivers/pci/controller/dwc/pcie-ultrarisc.c
> +++ b/drivers/pci/controller/dwc/pcie-ultrarisc.c
> @@ -154,12 +154,6 @@ static int ultrarisc_pcie_probe(struct platform_device *pdev)
>  
>  	pp = &pci->pp;
>  
> -	/*
> -	 * DP1000 routes MEM transactions without outbound iATU windows, which
> -	 * avoids the 16-window/4GB-per-window aperture limit.
> -	 */
> -	pp->bypass_ob_mem_iatu = true;
> -

[Severity: Low]
Does splitting this removal from the preceding commit ("PCI: dwc: Skip MEM
outbound iATU setup for identity mappings") break bisectability when
CONFIG_PCIE_ULTRARISC is enabled?

The preceding commit already removed the bypass_ob_mem_iatu field from
struct dw_pcie_rp in drivers/pci/controller/dwc/pcie-designware.h:

struct dw_pcie_rp {
	...
	bool			ecam_enabled;
	bool			native_ecam;
-	bool			bypass_ob_mem_iatu;
	bool                    skip_l23_ready;

while ultrarisc_pcie_probe() in drivers/pci/controller/dwc/pcie-ultrarisc.c
still sets pp->bypass_ob_mem_iatu = true until this patch, causing a build
failure at the intermediate commit.

Should this change be squashed into the preceding commit (whose commit
message already states "Remove bypass_ob_mem_iatu and the UltraRISC-specific
setting"), or ordered before the struct member is removed from
struct dw_pcie_rp?

>  	platform_set_drvdata(pdev, ultra);
>  
>  	ret = ultrarisc_pcie_init_clks(ultra);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261019-dw-pci-fix-v1-0-9b7860f919b9@ultrarisc.com?part=2