Re: [PATCH 2/3] soc/tegra: fuse: Store Tegra114 CPU and SoC speedo values

[Mikko Perttunen]

On Thursday, October 29, 2026 6:33 PM Patrick Fischer via B4 Relay wrote:
> From: Patrick Fischer <admin@xxxxxxxxxxxxxxxxxx>
> 
> The Tegra114 CPU DFLL computes its OPP voltages from the CVB tables
> added in commit 5aba939e80f4 ("clk: tegra: dfll: Add CVB tables for
> Tegra114"), using tegra_sku_info.cpu_speedo_value. The Tegra114 speedo
> code computes this value but never stores it, so the DFLL uses speedo
> 0 and only the c0 coefficient remains. For CPU speedo IDs 1 to 3 c0 is
> 2190643 to 3395401, so "mv * 1000" in round_cvb_voltage() overflows and
> the OPP voltages are wrong.
> 
> This is currently hidden by a zero voltage step with Palmas regulators,
> fixed in the next patch. With both fixes the CPU OPPs range from 1000 mV
> to 1270 mV on a device with CPU speedo 1742, which matches the vendor
> kernel.
> 
> Store the SoC speedo value as well, as Tegra124 and Tegra210 do.
> 
> Fixes: 5aba939e80f4 ("clk: tegra: dfll: Add CVB tables for Tegra114")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Patrick Fischer <admin@xxxxxxxxxxxxxxxxxx>
> ---
>  drivers/soc/tegra/fuse/speedo-tegra114.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/soc/tegra/fuse/speedo-tegra114.c b/drivers/soc/tegra/fuse/speedo-tegra114.c
> index 1e6c2b5be759..8bf1a1b1287a 100644
> --- a/drivers/soc/tegra/fuse/speedo-tegra114.c
> +++ b/drivers/soc/tegra/fuse/speedo-tegra114.c
> @@ -92,6 +92,9 @@ void __init tegra114_init_speedo_data(struct tegra_sku_info *sku_info)
>  	cpu_speedo_val = tegra_fuse_read_early(FUSE_CPU_SPEEDO_1) + 1024;
>  	soc_speedo_val = tegra_fuse_read_early(FUSE_SOC_SPEEDO_0);
>  
> +	sku_info->cpu_speedo_value = cpu_speedo_val;
> +	sku_info->soc_speedo_value = soc_speedo_val;
> +
>  	for (i = 0; i < CPU_PROCESS_CORNERS; i++)
>  		if (cpu_speedo_val < cpu_process_speedos[threshold][i])
>  			break;
> 
> -- 
> 2.56.0
> 
> 
> 

Reviewed-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
Tested-by: Mikko Perttunen <mperttunen@xxxxxxxxxx> # Dalmore