Re: [PATCH v2 20/24] arm64: dts: qcom: lemans: Reduce OS PDC DRV span to 0x10000

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Reducing the DT `reg` size to `0x10000` triggers a kernel boot warning and mapping override in the `qcom-pdc` driver.
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commit 35903595a207aeb5cc83a80438e763bb0fb48abe
Author: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>

arm64: dts: qcom: lemans: Reduce OS PDC DRV span to 0x10000

This commit reduces the OS PDC DRV register window from 0x30000 to
0x10000 bytes for the pdc node on the Lemans platform.

> diff --git a/arch/arm64/boot/dts/qcom/lemans.dtsi b/arch/arm64/boot/dts/qcom/lemans.dtsi
> index fe6e763518230..603d98002b405 100644
> --- a/arch/arm64/boot/dts/qcom/lemans.dtsi
> +++ b/arch/arm64/boot/dts/qcom/lemans.dtsi
> @@ -5543,7 +5543,7 @@ dispcc0: clock-controller@af00000 {
>  
>  		pdc: interrupt-controller@b220000 {
>  			compatible = "qcom,sa8775p-pdc", "qcom,pdc";
> -			reg = <0x0 0x0b220000 0x0 0x30000>,
> +			reg = <0x0 0x0b220000 0x0 0x10000>,
[Severity: Medium]
Will this reduction in the reg size trigger a boot warning from the qcom-pdc
driver?

Looking at drivers/irqchip/qcom-pdc.c:qcom_pdc_probe(), the driver hardcodes a
minimum resource size of 0x30000 (QCOM_PDC_SIZE):

drivers/irqchip/qcom-pdc.c:qcom_pdc_probe() {
	...
	res_size = max_t(resource_size_t, resource_size(&res), QCOM_PDC_SIZE);
	if (res_size > resource_size(&res))
		pr_warn("%pOF: invalid reg size, please fix DT\n", node);
	...
}

If the device tree size is less than 0x30000, the driver forcibly expands the
mapped size back to 0x30000 and unconditionally prints a warning.

Is there a companion patch to update the driver, or does this need to be fixed
to avoid the warning and actually reduce the mapped size in the kernel?

>  			      <0x0 0x17c000f0 0x0 0x64>;
>  			qcom,pdc-ranges = <0 480 40>,
>  					  <40 140 14>,

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Sashiko AI review · https://sashiko.dev/#/patchset/20260527094333.2311731-1-mukesh.ojha@oss.qualcomm.com?part=20