Re: [PATCH v2 22/24] arm64: dts: qcom: milos: 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 PDC `reg` size to 0x10000 triggers a boot warning from the `qcom-pdc` driver and fails to reduce the actual mapped memory size.
--

commit bd9d32425fcdb7b1f806e074d8d4e1621656dc67
Author: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>

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

This commit reduces the first reg entry size of the OS PDC DRV register
window on milos from 0x30000 to 0x10000 bytes.

> diff --git a/arch/arm64/boot/dts/qcom/milos.dtsi b/arch/arm64/boot/dts/qcom/milos.dtsi
> index 4a64a98a434b6..c2b25f0dec0cf 100644
> --- a/arch/arm64/boot/dts/qcom/milos.dtsi
> +++ b/arch/arm64/boot/dts/qcom/milos.dtsi
> @@ -1948,7 +1948,7 @@ dispcc: clock-controller@af00000 {
>  
>  		pdc: interrupt-controller@b220000 {
>  			compatible = "qcom,milos-pdc", "qcom,pdc";
> -			reg = <0x0 0x0b220000 0x0 0x30000>,
> +			reg = <0x0 0x0b220000 0x0 0x10000>,

[Severity: Medium]
Does this change trigger a warning in the pdc driver during boot?

Looking at drivers/irqchip/qcom-pdc.c, the driver hardcodes a minimum
mapping size:

#define QCOM_PDC_SIZE 0x30000

And in qcom_pdc_probe(), it forces the mapping to be at least that size:

    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);

Since the driver expands the mapping back to 0x30000 and prints this
warning when the devicetree size is smaller, it seems this patch will
pollute the kernel log without actually reducing the mapped memory region.

Should the qcom-pdc driver be updated to support the smaller size before
or alongside this devicetree change?

>  			      <0x0 0x174000f0 0x0 0x64>;
>  			interrupt-parent = <&intc>;
>

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260527094333.2311731-1-mukesh.ojha@oss.qualcomm.com?part=22