Hi Maxime, Warpme,
On Tue, 28 Apr 2020 at 16:26, Clément Péron <peron.clem@xxxxxxxxx> wrote:
>
> Tanix TX6 has a fixed regulator. As DVFS is instructed to change
> voltage to meet OPP table, the DVFS is not working as expected.
>
> Avoid to introduce a new dedicated OPP Table where voltage are
> equals to the fixed regulator as it will only duplicate all the OPPs.
> Instead remove the fixed regulator so the DVFS framework will create
> dummy regulator and will have the same behavior.
>
> Add some comments to explain this in the device-tree.
Changes since v1:
I have change this patch to use dummy regulator and add comment about
this choice.
I think it's a bit better than just dropping the regulator.
@Piotr Oniszczuk:
Please add your tested-by tag, to be sure this is working as expected !
Thanks & Regards
Clement
>
> Reported-by: Piotr Oniszczuk <warpme@xxxxx>
> Fixes: add1e27fb703 ("arm64: dts: allwinner: h6: Enable CPU opp tables for Tanix TX6")
> Signed-off-by: Clément Péron <peron.clem@xxxxxxxxx>
> ---
> .../boot/dts/allwinner/sun50i-h6-tanix-tx6.dts | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6-tanix-tx6.dts b/arch/arm64/boot/dts/allwinner/sun50i-h6-tanix-tx6.dts
> index be81330db14f..3e96fcb317ea 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-h6-tanix-tx6.dts
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-h6-tanix-tx6.dts
> @@ -48,7 +48,15 @@
> };
>
> &cpu0 {
> - cpu-supply = <®_vdd_cpu_gpu>;
> + /*
> + * Don't specify the CPU regulator, as it's a fixed
> + * regulator DVFS will not work as it is intructed
> + * to reach a voltage which can't be reached.
> + * Not specifying a regulator will create a dummy
> + * regulator allowing all OPPs.
> + *
> + * cpu-supply = <®_vdd_cpu_gpu>;
> + */
> };
>
> &de {
> @@ -68,7 +76,13 @@
> };
>
> &gpu {
> - mali-supply = <®_vdd_cpu_gpu>;
> + /*
> + * Don't specify the GPU regulator, see comment
> + * above for the CPU supply.
> + *
> + * mali-supply = <®_vdd_cpu_gpu>;
> + */
> +
> status = "okay";
> };
>
> --
> 2.20.1
>
