5.4-stable review patch. If anyone has any objections, please let me know.
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From: Andre Przywara andre.przywara@arm.com
[ Upstream commit dd36ad71ad65968f97630808bc8d605c929b128e ]
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@arm.com Fixes: 1e1dea72651b ("ARM: dts: sun9i: cubieboard4: Add AXP809 PMIC device node and regulators") Link: https://patch.msgid.link/20241007222916.19013-1-andre.przywara@arm.com Signed-off-by: Chen-Yu Tsai wens@csie.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/boot/dts/sun9i-a80-cubieboard4.dts | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts b/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts index 484b93df20cb6..c7a3bf3cc3407 100644 --- a/arch/arm/boot/dts/sun9i-a80-cubieboard4.dts +++ b/arch/arm/boot/dts/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"; };