Re: [PATCH] slimbus: qcom-ngd-ctrl: fix ngd register base address

[Luca Weiss <luca@lucaweiss.eu>]

Hi Federico,

On 2026-07-09 19:00, Federico Amedeo Izzo via B4 Relay wrote:
> From: Federico Amedeo Izzo <federico@izzo.pro>
> 
> The slimbus controller register base was calculated using the
> controller ID and the register size, producing wrong results for ID > 
> 1.
> 
> The expression reduces to ngd->base = ctrl->base for controller with ID 
> = 1;
> but for ID > 1 the other factors produce a wrong base address.
> This bug caused a crash while trying to bring-up the secondary
> slimbus controller (ID = 3) on oneplus-enchilada with sdm845.
> 
> In practice, the correct base address for each slimbus controller can 
> be
> obtained from the device-tree, so there is no need for further
> calculations.
> 
> This was validated by reading the version register from the WCN3990 
> slim
> interface on oneplus-enchilada.
> 
> ---

Please remove the ---, otherwise your S-o-b will be dropped when 
applying the patch.

Also Fixes: ?

> Signed-off-by: Federico Amedeo Izzo <federico@izzo.pro>
> ---
>  drivers/slimbus/qcom-ngd-ctrl.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/slimbus/qcom-ngd-ctrl.c 
> b/drivers/slimbus/qcom-ngd-ctrl.c
> index 80877e951849..91932f8d021b 100644
> --- a/drivers/slimbus/qcom-ngd-ctrl.c
> +++ b/drivers/slimbus/qcom-ngd-ctrl.c
> @@ -1547,8 +1547,7 @@ static int of_qcom_slim_ngd_register(struct 
> device *parent,
>  			kfree(ngd);
>  			return ret;
>  		}
> -		ngd->base = ctrl->base + ngd->id * data->offset +
> -					(ngd->id - 1) * data->size;
> +		ngd->base = ctrl->base + data->offset;
> 
>  		return 0;
>  	}
> 
> ---
> base-commit: b9810cd75b9fb56a3425d391cba3f608502bd474
> change-id: 20260709-qcom-ngd-register-base-fix-a59713a184b8
> 
> Best regards,
> --
> Federico Amedeo Izzo <federico@izzo.pro>