Re: [PATCH RFC] power: reset: qcom-pon: Drop reason shift for PMK8350

[Dmitry Baryshkov]

On Mon, Sep 07, 2026 at 04:44:29PM +0000, Alexander Koskovich wrote:
> On the PMK8350 the SOFT_RB_SPARE register does not exist, the reset
> reason is instead kept in SDAM and written through the reboot-reason
> nvmem cell.
> 
> Signed-off-by: Alexander Koskovich <akoskovich@xxxxx>
> ---
> Would like some feedback on this as I'm seeing conflicting results,
> SOFT_RB_SPARE does not exist on HLOS but it looks like the downstream
> qpnp-power-on driver writes to XVDD_RB_SPARE2 for GEN3, which is on PBS.
> 
> Though, targets like waipio don't seem to have access to write to PBS
> from HLOS? Get SPMI errors when I try. Didn't have an issue doing so on
> milos though.

It well might be that the PMIC has the spare register but whether it
gets used or not depends on the platform (and the firmware) rather than
the PMIC.

> 
> Besides, the bindings doesn't allow reboot modes on PMK8350 so maybe
> setting no reason shift is correct regardless so it gets skipped?
> ---
>  drivers/power/reset/qcom-pon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/power/reset/qcom-pon.c b/drivers/power/reset/qcom-pon.c
> index 7e108982a582..9cd55f5536b4 100644
> --- a/drivers/power/reset/qcom-pon.c
> +++ b/drivers/power/reset/qcom-pon.c
> @@ -90,7 +90,7 @@ static const struct of_device_id qcom_pon_id_table[] = {
>  	{ .compatible = "qcom,pm8941-pon", .data = (void *)NO_REASON_SHIFT },
>  	{ .compatible = "qcom,pms405-pon", .data = (void *)GEN1_REASON_SHIFT },
>  	{ .compatible = "qcom,pm8998-pon", .data = (void *)GEN2_REASON_SHIFT },
> -	{ .compatible = "qcom,pmk8350-pon", .data = (void *)GEN2_REASON_SHIFT },
> +	{ .compatible = "qcom,pmk8350-pon", .data = (void *)NO_REASON_SHIFT },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, qcom_pon_id_table);
> 
> ---
> base-commit: 944a035ecca915ae947905dcfb03f2b9dc6d032c
> change-id: 20260907-pon-pbs-76b7ecaafe33
> 
> Best regards,
> -- 
> Alexander Koskovich <akoskovich@xxxxx>
> 
> 

-- 
With best wishes
Dmitry