On Fri, 25 Oct 2024 22:42:14 +0800
Chen-Yu Tsai <wens@xxxxxxxx> wrote:
> On Tue, Oct 8, 2024 at 6:30 AM Andre Przywara <andre.przywara@xxxxxxx> wrote:
> >
> > The DCDC5 voltage rail in the X-Powers AXP809 PMIC has a resolution of
> > 50mV, so the currently enforced limits of 1.475 and 1.525 volts cannot
> > be set, when the existing regulator value is beyond this range.
> >
> > This will lead to the whole regulator driver to give up and fail
> > probing, which in turn will hang the system, as essential devices depend
> > on the PMIC.
> > In this case a bug in U-Boot set the voltage to 1.75V (meant for DCDC4),
> > and the AXP driver's attempt to correct this lead to this error:
> > ==================
> > [ 4.447653] axp20x-rsb sunxi-rsb-3a3: AXP20X driver loaded
> > [ 4.450066] vcc-dram: Bringing 1750000uV into 1575000-1575000uV
> > [ 4.460272] vcc-dram: failed to apply 1575000-1575000uV constraint: -EINVAL
> > [ 4.474788] axp20x-regulator axp20x-regulator.0: Failed to register dcdc5
> > [ 4.482276] axp20x-regulator axp20x-regulator.0: probe with driver axp20x-regulator failed with error -22
> > ==================
> >
> > Set the limits to values that can be programmed, so any correction will
> > be successful.
> >
> > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
>
> Maybe
>
> Fixes: 1e1dea72651b ("ARM: dts: sun9i: cubieboard4: Add AXP809 PMIC
> device node and regulators")
>
> What do you think? I can add it when applying.
Well, I thought about it, but then it's a DT patch, so the Fixes: tag
doesn't make much sense here, IMHO. Put it there if you see fit, but for
my part I am just waiting for the commit hash, to pull into U-Boot, and
then it would be done, even for older kernels.
Cheers,
Andre.
> ChenYu
>
> > ---
> > arch/arm/boot/dts/allwinner/sun9i-a80-cubieboard4.dts | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm/boot/dts/allwinner/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/allwinner/sun9i-a80-cubieboard4.dts
> > index c8ca8cb7f5c94..52ad95a2063aa 100644
> > --- a/arch/arm/boot/dts/allwinner/sun9i-a80-cubieboard4.dts
> > +++ b/arch/arm/boot/dts/allwinner/sun9i-a80-cubieboard4.dts
> > @@ -280,8 +280,8 @@ reg_dcdc4: dcdc4 {
> >
> > reg_dcdc5: dcdc5 {
> > regulator-always-on;
> > - regulator-min-microvolt = <1425000>;
> > - regulator-max-microvolt = <1575000>;
> > + regulator-min-microvolt = <1450000>;
> > + regulator-max-microvolt = <1550000>;
> > regulator-name = "vcc-dram";
> > };
> >
> > --
> > 2.46.2
> >
