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: petrben@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Petr Benes <petr.benes@ysoft.com>
Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

diff --git a/arch/arm/boot/dts/imx6q-yapp4-crux.dts b/arch/arm/boot/dts/imx6q-yapp4-crux.dts
index 15f4824..bddf382 100644 (file)
--- a/arch/arm/boot/dts/imx6q-yapp4-crux.dts
+++ b/arch/arm/boot/dts/imx6q-yapp4-crux.dts
@@ -33,6 +33,10 @@
        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 cea165f..afaf4a6 100644 (file)
--- a/arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts
+++ b/arch/arm/boot/dts/imx6qp-yapp4-crux-plus.dts
@@ -33,6 +33,10 @@
        status = "okay";
 };
 
+&reg_pu {
+       regulator-always-on;
+};
+
 &reg_usb_h1_vbus {
        status = "okay";
 };