Re: [PATCH 1/1] PCI: imx6: Use dev_err_probe

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The return value of imx_pcie_host_init() is ignored in imx_add_pcie_ep(), leading to a system crash when pwrctrl devices trigger a probe deferral.
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commit 177305e0f76751d4a9bafb983aa8f962639d5a3b
Author: Alexander Stein <alexander.stein@ew.tq-group.com>

PCI: imx6: Use dev_err_probe

pci_pwrctrl_power_on_devices() might return -EPROBE_DEFER resulting in
an error message. Use dev_err_probe to silence this non-error message.

> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 98e1db751132a..b7a502e9a1c59 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1381,7 +1381,7 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
>  
>  	ret = pci_pwrctrl_power_on_devices(dev);
>  	if (ret) {
> -		dev_err(dev, "failed to power on pwrctrl devices\n");
> +		dev_err_probe(dev, ret, "failed to power on pwrctrl devices\n");

[Severity: High]
This isn't a bug introduced by this patch, but since 
pci_pwrctrl_power_on_devices() might return -EPROBE_DEFER (as anticipated by
this change), does this lead to a system crash during endpoint initialization?

In drivers/pci/controller/dwc/pci-imx6.c:imx_add_pcie_ep(),
imx_pcie_host_init() is called but its return value is ignored:

	imx_pcie_host_init(pp);
	ep = &pci->ep;

If imx_pcie_host_init() fails and returns -EPROBE_DEFER, imx_add_pcie_ep()
blindly proceeds to execute dw_pcie_ep_init_registers() and
imx_pcie_host_post_init() on unpowered hardware.

This causes the kernel to attempt MMIO reads and writes on unclocked and
unpowered PCIe Endpoint DBI registers, which triggers a synchronous external
abort and panics the system on ARM/i.MX platforms.

Could we add a check for the return value of imx_pcie_host_init() in
imx_add_pcie_ep()?

>  		goto err_pwrctrl_destroy;
>  	}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260619112535.1127850-1-alexander.stein@ew.tq-group.com?part=1