Getting Errors When Deploying Device Tree Overlays

I am working on learning how to use device tree overlays in my Beaglebone Black.

The Linux version is:

Linux version 4.1.18-ti-r52 (root@b1-omap5-uevm-2gb) (gcc version 4.9.2 (Debian 4.9.2-10) ) #1 SMP Thu Mar 10 00:41:28 UTC 2016

I am following the example at

https://github.com/jadonk/validation-scripts/blob/master/test-capemgr/README.md. I have also worked through the examples in Derek Molloys’ Exploring BeagleBone Black book chapter 6. In both of those cases I am running into the same errors when I deploy the overlay. The overlay appears to deploy properly, no errors are given when doing echo > $SLOTS but when I look at the kernel messages using dmesg I get errors like what is shown below. What is shown below is from following the jadonk example.

[ 1053.452639] bone_capemgr bone_capemgr: Using override eeprom data at slot 5

[ 1053.452664] bone_capemgr bone_capemgr: slot #5: ‘Override Board Name,00A0,Override Manuf,pinctrl-test-7’

[ 1053.455556] pinctrl-single 44e10800.pinmux: pin 44e10964.0 already requested by ocp:P9_42_pinmux; cannot claim for ocp:helper

[ 1053.467142] pinctrl-single 44e10800.pinmux: pin-89 (ocp:helper) status -22

[ 1053.474093] pinctrl-single 44e10800.pinmux: could not request pin 89 (44e10964.0) from group pinctrl_test_7_pins on device pinctrl-single

[ 1053.486626] bone-pinmux-helper ocp:helper: Error applying setting, reverse things back

[ 1053.495157] pinctrl-single 44e10800.pinmux: pin 44e10964.0 already requested by ocp:P9_42_pinmux; cannot claim for ocp:helper

[ 1053.506627] pinctrl-single 44e10800.pinmux: pin-89 (ocp:helper) status -22

[ 1053.513582] pinctrl-single 44e10800.pinmux: could not request pin 89 (44e10964.0) from group pinctrl_test_7_pins on device pinctrl-single

[ 1053.526118] bone-pinmux-helper ocp:helper: Error applying setting, reverse things back

[ 1053.534109] bone-pinmux-helper ocp:helper: Failed to select default state

Before deploy I see:

root@beaglebone:/lib/firmware# cat $SLOTS

0: PF---- -1

1: PF---- -1

2: PF---- -1

3: PF---- -1

4: P-O-L- 0 Override Board Name,00A0,Override Manuf,cape-universaln

After deploy I see:

root@beaglebone:/lib/firmware# cat $SLOTS

0: PF---- -1

1: PF---- -1

2: PF---- -1

3: PF---- -1

4: P-O-L- 0 Override Board Name,00A0,Override Manuf,cape-universaln

5: P-O-L- 1 Override Board Name,00A0,Override Manuf,pinctrl-test-7

But dmesg shows the errors above.

Can you suggest what might be happening and/or how I might troubleshoot the problem?

Thanks.

Randy Canegaly

I am past this problem. On another forum, cape-universaln and usage of config-pin was explained to me. cape-universaln is an overlay that provides a way to configure pins without writing overlays. There is good information on this at beaglebone-universal-io. The pin conflicts I was seeing were to be expected. I was trying to deploy an unneeded overlay on top of an already deployed overlay that provided a simpler way to configure pins. Still learning.