A general comment is that the Device Tree system is not robust! I gave up on modifying Device Trees a long time ago. I'm using the "Universal IO" whenever possible:
https://github.com/cdsteinkuehler/beaglebone-universal-io Avoid touching Device Tree files if you can! AVOID I just set up the latest Debian IOT image, and Universal IO is already installed. Both images I tested this morning have unstable Device Trees. Here is the error from dmesg. This happens after echo -4 > slots in the directory /sys/devices/platform/bone_capemgr [ 73.214648] bone_capemgr bone_capemgr: slot #4: dtbo 'univ-emmc-00A0.dtbo' loaded; overlay id #0 [ 75.337937] eqep 48300180.eqep: ver. 1.0 [ 75.359258] eqep 48302180.eqep: ver. 1.0 [ 75.381966] eqep 48304180.eqep: ver. 1.0 [ 75.527919] CAN device driver interface [ 75.638311] c_can_platform 481cc000.can: c_can_platform device registered (regs=fa1cc000, irq=196) [ 75.666734] c_can_platform 481d0000.can: c_can_platform device registered (regs=fa1d0000, irq=197) [ 274.607591] Unable to handle kernel NULL pointer dereference at virtual address 0000000d [ 274.616173] pgd = db704000 [ 274.618938] [0000000d] *pgd=9c68a831, *pte=00000000, *ppte=00000000 [ 274.625554] Internal error: Oops: 17 [#1] SMP ARM [ 274.630319] Modules linked in: spidev c_can_platform c_can can_dev spi_omap2_mcspi pwm_tiecap tieqep pwm_tiehrpwm usb_f_acm u_serial usb_f_rndis g_multi usb_f_mass_storage u_ether libcomposite omap_aes_driver omap_sham omap_rng rng_core evdev uio_pdrv_genirq uio 8021q garp mrp stp llc I predict I will be able to work with this image as long as I don't do anything to Device Tree and don't touch the slots!!! Regards, Greg -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/24dc582b-6dcf-4bac-8f85-8752c2c64aa5%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
