Re: [PATCH v14 10/12] iio: frequency: adf41513: features on frequency change

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Bleed current is not computed or updated when switching from Integer-N to Fractional-N mode if the PFD frequency remains unchanged.
--

commit 299bd27511dd5b2a2354c749631d53bcff158e2b
Author: Rodrigo Alencar <rodrigo.alencar@analog.com>

iio: frequency: adf41513: features on frequency change

This commit adds bleed current configuration, lock detector window adjustments,
and phase resync support to the ADF41513 driver when changing the PFD
frequency.

> diff --git a/drivers/iio/frequency/adf41513.c b/drivers/iio/frequency/adf41513.c
> --- a/drivers/iio/frequency/adf41513.c
> +++ b/drivers/iio/frequency/adf41513.c

[ ... ]

> +static void adf41513_set_bleed_val(struct adf41513_state *st)
> +{
> +	u32 bleed_value, cp_index;
> +
> +	if (!(st->regs[ADF41513_REG6] & ADF41513_REG6_BLEED_ENABLE_MSK))
> +		return;

[ ... ]

> @@ -630,6 +725,14 @@ static int adf41513_set_frequency(struct adf41513_state *st, u64 freq_uhz, u16 s
>  		st->regs[ADF41513_REG6] |= ADF41513_REG6_BLEED_ENABLE_MSK;
>  	}
>  
> +	if (pfd_change) {
> +		adf41513_set_bleed_val(st);

[Severity: High]
Will the bleed current be properly configured if the device switches
from Integer-N to Fractional-N mode without changing the PFD frequency?

In adf41513_set_bleed_val(), if the device is previously in Integer-N mode,
ADF41513_REG6_BLEED_ENABLE_MSK is cleared. If the PFD frequency changes
while in Integer-N mode, adf41513_set_bleed_val() returns early without
updating the register.

If a subsequent frequency change switches the PLL to Fractional-N mode but
maintains the exact same PFD frequency, pfd_change will be false. Since
adf41513_set_bleed_val() is only called when pfd_change is true, the bleed
value configuration gets skipped entirely.

Could this leave the bleed circuit enabled with a stale or uninitialized
current value, potentially preventing the PLL from locking?

> +		adf41513_set_phase_resync(st);
> +	}
> +
> +	if (pfd_change || mode_change)
> +		adf41513_set_ld_window(st);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260524-adf41513-iio-driver-v14-0-06824d9c15f4@analog.com?part=10