Re: [PATCH v5 07/12] clk: ambarella: add CV75 CCU driver

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Casting away `const` to modify a `const`-qualified array member via `memcpy` invokes undefined behavior.
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--- Patch [7]: [PATCH v5 07/12] clk: ambarella: add CV75 CCU driver ---
commit 477493a502606783178c884c88d17f74d16fc602
Author: Long Zhao <[email protected]>

clk: ambarella: add CV75 CCU driver

Add the Ambarella CV75 clock driver covering the core PLL and the UART0
/ AHB / APB clocks needed for early console bring-up.

> diff --git a/drivers/clk/ambarella/ccu-cv75.c b/drivers/clk/ambarella/ccu-cv75.c
> index 0000000000000..d682da3cf28d3
> --- /dev/null
> +++ b/drivers/clk/ambarella/ccu-cv75.c

[ ... ]

> +static struct clk_hw *amb_cv75_register_clk(struct device *dev,
> +					    struct amb_ccu *ccu,
> +					    const struct amb_cv75_clk_desc *desc,
> +					    struct clk_hw *osc,
> +					    struct clk_hw *dummy)
> +{
> +	struct amb_pll_desc pll_desc;
> +	struct clk_hw *parent;
> +
> +	switch (desc->type) {

[ ... ]

> +	case AMB_CV75_CLK_PLL:
> +		parent = amb_cv75_get_parent(ccu, osc, dummy, desc->parent);
> +		if (IS_ERR(parent))
> +			return parent;
> +
> +		pll_desc.name = desc->name;
> +		pll_desc.parent = parent;
> +		memcpy((void *)pll_desc.reg_offset, desc->pll.reg_offset,
> +		       sizeof(pll_desc.reg_offset));

[Severity: Low]
Is it safe to cast away the const qualifier here? 

The reg_offset array in struct amb_pll_desc is defined as const u32. Modifying
a const-qualified object through a non-const pointer like this results in
undefined behavior under C language rules.

Could this be refactored so that the struct initialization doesn't require
casting away const?

> +		pll_desc.soc_data = desc->pll.soc_data;
> +		pll_desc.frac_mode = false;
> +
> +		return amb_pll_register(dev, ccu->map, &pll_desc);

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=7