Re: [PATCH 2/4] clk: qcom: clk-alpha-pll: Skip Zonda PLL configuration if already enabled

[Konrad Dybcio]

On 10/7/26 8:50 AM, Kathiravan Thirumoorthy wrote:
> On IPQ9650, the bootloader configures and enables the APSS Zonda PLL
> that provide the clocks for the A55 CPU cores and L3 interconnect. When
> the APSS clock driver probes, it attempts to reconfigure the already
> running PLLs. As part of the reconfiguration sequence, the PLL output is
> disabled and the PLL is placed into standby before being re-enabled.
> Since the CPUs are actively clocked from these PLLs, removing the clock
> during this window causes the system to hang.
> 
> Avoid reconfiguring PLLs that are already enabled and return early,
> similar to clk_trion_pll_configure().
> 
> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
> ---
>  drivers/clk/qcom/clk-alpha-pll.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
> index 60173b076cc5..3641b2da92cd 100644
> --- a/drivers/clk/qcom/clk-alpha-pll.c
> +++ b/drivers/clk/qcom/clk-alpha-pll.c
> @@ -2162,6 +2162,10 @@ EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_lucid_5lpe_ops);
>  void clk_zonda_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>  			     const struct alpha_pll_config *config)
>  {
> +	/* Check if PLL is already enabled */
> +	if (trion_pll_is_enabled(pll, regmap))
> +		return;

Please add a debug print to match the other similar calls

with that:

Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>

Konrad