Re: [PATCH v6 02/16] clk: qcom: gcc-qcm2290: Keep the critical clocks always-on from probe

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Placing a voting register in the clk_cbcrs array misuses the CBCR API and introduces a fragile pattern.
--

--- Patch [2]: [PATCH v6 02/16] clk: qcom: gcc-qcm2290: Keep the critical clocks always-on from probe ---
commit d7a7b99958c3ce75a0a25d8faec4383b5f406ac6
Author: Imran Shaik <imran.shaik@oss.qualcomm.com>

clk: qcom: gcc-qcm2290: Keep the critical clocks always-on from probe

This commit drops the modeling of certain always-on QCM2290 GCC branch clocks
and instead uses the .clk_cbcr convention to keep them enabled from probe.

> diff --git a/drivers/clk/qcom/gcc-qcm2290.c b/drivers/clk/qcom/gcc-qcm2290.c
> --- a/drivers/clk/qcom/gcc-qcm2290.c
> +++ b/drivers/clk/qcom/gcc-qcm2290.c

[ ... ]

> @@ -2943,6 +2845,15 @@ static struct gdsc *gcc_qcm2290_gdscs[] = {
>  	[HLOS1_VOTE_MM_SNOC_MMU_TBU_NRT_GDSC] = &hlos1_vote_mm_snoc_mmu_tbu_nrt_gdsc,
>  };
>  
> +static const u32 gcc_qcm2290_critical_cbcrs[] = {
> +	0x17008, /* GCC_CAMERA_AHB_CLK */
> +	0x17028, /* GCC_CAMERA_XO_CLK */
> +	0x1700c, /* GCC_DISP_AHB_CLK */
> +	0x1702c, /* GCC_DISP_XO_CLK */
> +	0x36004, /* GCC_GPU_CFG_AHB_CLK */
> +	0x79004, /* GCC_SYS_NOC_CPUSS_AHB_CLK */

[Severity: Low]
Does this code misuse the clk_cbcrs array? Register 0x79004 is a shared
voting register rather than a standard Clock Branch Control Register (CBCR).

Looking at how the API handles clk_cbcrs, the helper
qcom_branch_set_clk_en() unconditionally updates BIT(0) (the standard
CBCR enable bit).

While this functions correctly for GCC_SYS_NOC_CPUSS_AHB_CLK simply because
its voting mask happens to be exactly BIT(0), doesn't this introduce a
fragile pattern?

If this is copied for other voting clocks with different masks (such as
BIT(15)), won't it silently corrupt the voting register state and fail to
enable the intended clock?

> +};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260718-shikra-dispcc-gpucc-v6-0-62703e05ef0f@oss.qualcomm.com?part=2