2022-10-04 16:53:48

by Petr Benes

Subject: [PATCH] ARM: dts: imx6dl-yapp4: Do not allow PM to switch PU regulator off on Q/QP

Fix our design flaw in supply voltage distribution on the Quad and QuadPlus
based boards.

The problem is that we supply the SoC cache (VDD_CACHE_CAP) from VDD_PU
instead of VDD_SOC. The VDD_PU internal regulator can be disabled by PM
if VPU or GPU is not used. If that happens the system freezes. To prevent
that configure the reg_pu regulator to be always on.

Fixes: 0de4ab81ab26 ("ARM: dts: imx6dl-yapp4: Add Y Soft IOTA Crux/Crux+ board")
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Petr Benes <[email protected]>
Signed-off-by: Michal Vokáč <[email protected]>
---
arch/arm/boot/dts/imx6q-yapp4-crux.dts | 4 ++++
arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts | 4 ++++
2 files changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/imx6q-yapp4-crux.dts b/arch/arm/boot/dts/imx6q-yapp4-crux.dts
index deb18c57cf18..22f647eb12e7 100644
--- a/arch/arm/boot/dts/imx6q-yapp4-crux.dts
+++ b/arch/arm/boot/dts/imx6q-yapp4-crux.dts
@@ -45,6 +45,10 @@ &oled_1309 {
status = "okay";
};

+&reg_pu {
+ regulator-always-on;
+};
+
&reg_usb_h1_vbus {
status = "okay";
};
diff --git a/arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts b/arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts
index a450a77f920f..b580ce891f7e 100644
--- a/arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts
+++ b/arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts
@@ -45,6 +45,10 @@ &oled_1309 {
status = "okay";
};

+&reg_pu {
+ regulator-always-on;
+};
+
&reg_usb_h1_vbus {
status = "okay";
};
--
2.25.1

2022-10-24 02:36:55

by Shawn Guo

Subject: Re: [PATCH] ARM: dts: imx6dl-yapp4: Do not allow PM to switch PU regulator off on Q/QP

On Tue, Oct 04, 2022 at 05:39:20PM +0200, Petr Benes wrote:
> Fix our design flaw in supply voltage distribution on the Quad and QuadPlus
> based boards.
>
> The problem is that we supply the SoC cache (VDD_CACHE_CAP) from VDD_PU
> instead of VDD_SOC. The VDD_PU internal regulator can be disabled by PM
> if VPU or GPU is not used. If that happens the system freezes. To prevent
> that configure the reg_pu regulator to be always on.
>
> Fixes: 0de4ab81ab26 ("ARM: dts: imx6dl-yapp4: Add Y Soft IOTA Crux/Crux+ board")
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Petr Benes <[email protected]>
> Signed-off-by: Michal Vokáč <[email protected]>

Applied, thanks!