device tree overlay strange persistence using rcn's 8.4_console_4/7/2016 + 4.4.9-bone-rt-r10

[Super Twang]

I'm seeing some strange persistent/erroneous behavior with a device tree overlay that I wanted to ask about.

Specifically, I'm seeing startup errors in 'dmesg' which reference symbols in a device tree overlay (.dtbo) that no longer exist.

[   11.591461] pinctrl-single 44e10800.pinmux: bad data for mux MYOVERLAY_pru

[   11.671379] pinctrl-single 44e10800.pinmux: no pins entries for MYOVERLAY_pru

I'm using image:

  bone-debian-8.4-console-armhf-2016-04-07-2gb.img.xz

(With some packages removed)

I'm using kernel:

  4.4.9-bone-rt-r10

The errors originated from an old *.dtc file that did indeed contain errors (no pins defined for a mux called MYOVERLAY_pru).  So, I simplified it, created a 'good' version of the *dtc, which compiles and loads properly.  The new overlay doesn't contain ANY references to MYOVERLAY_pru, and yet, I'm still seeing errors referencing it on reboot (when the part is enabled in /boot/uEnv.txt), when I type 'dmesg'

Also, if it is helpful, I've found that the directory below seems to appear with the error messages.

/sys/firmware/devicetree/base/ocp/l4_wkup@44c00000/scm@210000/pinmux@800/MYOVERLAY_pru

I've tried disabling the part in /boot/uEnv.txt, and rebooting.

I've tried doing a full halt, then disconnecting power for several minutes, then rebooting.

I can make the errors go away if I disable the part in /boot/uEnv.txt, but, I actually want the (correct) overlay to load (with no errors) upon startup.

Does anyone have any idea what is going on here?  How can a symbol from a device tree overlay persist beyond its own deletion/de-install?  Is something being saved, but then not cleared from persistent memory?

Thanks for any insights you might have,

ST

PS. I've attached the two *dtc files in question below

----------------------------------- BELOW IS THE ORIG DTC WHICH CAUSED THE ERROR

/dts-v1/;

/ {

compatible = "ti,beaglebone-black";

part-number = "MY_OVERLAY";

version = "00A0";

exclusive-use = "P8.12", "pruss", "pru0";

fragment@0 {

target = <0xdeadbeef>;

__overlay__ {

MY_OVERLAY_gpio {

pinctrl-single,pins = <0x30 0x7>;

linux,phandle = <0x2>;

phandle = <0x2>;

};

MY_OVERLAY_pru {

pinctrl-single,pins;       // <----- NOTE, THE LACK OF PIN DEFS HERE CAUSES THE ERROR MESSAGE(I think)

linux,phandle = <0x1>;

phandle = <0x1>;

};

};

};

fragment@1 {

target = <0xdeadbeef>;

__overlay__ {

status = "okay";

pinctrl-names = "default";

pinctrl-0 = <0x1>;

};

};

fragment@2 {

target = <0xdeadbeef>;

__overlay__ {

gpio_helper {

compatible = "gpio-of-helper";

status = "okay";

pinctrl-names = "default";

pinctrl-0 = <0x2>;

};

};

};

__symbols__ {

my_overlay_gpio = "/fragment@0/__overlay__/MY_OVERLAY_gpio";

my_overlay_pru = "/fragment@0/__overlay__/MY_OVERLAY_pru";

};

__local_fixups__ {

fragment@1 {

__overlay__ {

pinctrl-0 = <0x0>;

};

};

fragment@2 {

__overlay__ {

gpio_helper {

pinctrl-0 = <0x0>;

};

};

};

};

__fixups__ {

am33xx_pinmux = "/fragment@0:target:0";

pruss = "/fragment@1:target:0";

ocp = "/fragment@2:target:0";

};

};

----------------------------------- BELOW IS THE FIXED DTC 

/dts-v1/;

/ {

compatible = "ti,beaglebone-black";

part-number = "MY_OVERLAY";

version = "00A0";

exclusive-use = "P8.12";

fragment@0 {

target = <0xdeadbeef>;

__overlay__ {

MY_OVERLAY_gpio {

pinctrl-single,pins = <0x30 0x7>;

linux,phandle = <0x1>;

phandle = <0x1>;

};

};

};

fragment@1 {

target = <0xdeadbeef>;

__overlay__ {

gpio_helper {

compatible = "gpio-of-helper";

status = "okay";

pinctrl-names = "default";

pinctrl-0 = <0x1>;

};

};

};

__symbols__ {

my_overlay_gpio = "/fragment@0/__overlay__/MY_OVERLAY_gpio";

};

__local_fixups__ {

fragment@1 {

__overlay__ {

gpio_helper {

pinctrl-0 = <0x0>;

};

};

};

};

__fixups__ {

am33xx_pinmux = "/fragment@0:target:0";

ocp = "/fragment@1:target:0";

};

};