Dear developers, Following Jason Kridner's advice I'm posting here an issue found while working with the BeagleBone and an RT_PREEMPT patched kernel (3.8 taken from https://github.com/beagleboard/kernel/tree/3.8-rt). The problem seems to be a conflict with the capemgr implemented in the BeagleBone. Particularly the problem arised when this overlay (https://github.com/BeaglePilot/ardupilot/blob/master/libraries/AP_HAL_Linux/PRU/test_overlays/BB-BONE-PRU-05-00A0.dts) was loaded but the same behavior has been detected with other overlays (UART or I2C busses overlays create a similar result): [ 56.849553] bone-capemgr bone_capemgr.8: part_number 'BB-BONE-PRU-05', version 'N/A' [ 56.850629] bone-capemgr bone_capemgr.8: slot #4: generic override [ 56.850661] bone-capemgr bone_capemgr.8: bone: Using override eeprom data at slot 4 [ 56.850687] bone-capemgr bone_capemgr.8: slot #4: 'Override Board Name,00A0,Override Manuf,BB-BONE-PRU-05' [ 56.850866] bone-capemgr bone_capemgr.8: slot #4: Requesting part number/version based 'BB-BONE-PRU-05-00A0.dtbo [ 56.850894] bone-capemgr bone_capemgr.8: slot #4: Requesting firmware 'BB-BONE-PRU-05-00A0.dtbo' for board-name 'Override Board Name', version '00A0' [ 56.856248] bone-capemgr bone_capemgr.8: slot #4: dtbo 'BB-BONE-PRU-05-00A0.dtbo' loaded; converting to live tree [ 56.856408] BUG: rwlock bad magic on CPU#0, bash/688, c07021f4 [ 56.862638] [] (unwind_backtrace+0x1/0x8a) from [] (do_raw_read_lock+0x13/0x38) [ 56.872186] [] (do_raw_read_lock+0x13/0x38) from [] (of_resolve+0x27/0x370) [ 56.881348] [] (of_resolve+0x27/0x370) from [] (bone_capemgr_load+0x175/0x408) [ 56.890787] [] (bone_capemgr_load+0x175/0x408) from [] (slots_store+0x22b/0x26c) [ 56.900409] [] (slots_store+0x22b/0x26c) from [] (dev_attr_store+0xb/0x12) [ 56.909495] [] (dev_attr_store+0xb/0x12) from [] (sysfs_write_file+0xa3/0xda) [ 56.918847] [] (sysfs_write_file+0xa3/0xda) from [] (vfs_write+0x5d/0x100) [ 56.927910] [] (vfs_write+0x5d/0x100) from [] (sys_write+0x27/0x44) [ 56.936335] [] (sys_write+0x27/0x44) from [] (ret_fast_syscall+0x1/0x46) [ 56.948739] bone-capemgr bone_capemgr.8: slot #4: #2 overlays [ 56.973249] omap_hwmod: pruss: failed to hardreset [ 56.985351] remoteproc0: 4a300000.prurproc is available [ 56.998312] remoteproc0: Note: remoteproc is still under development and considered experimental. [ 57.018198] remoteproc0: THE BINARY FORMAT IS NOT YET FINALIZED, and backward compatibility isn't yet guaranteed. [ 57.030780] pru-rproc 4a300000.prurproc: Loaded OK [ 57.041467] bone-capemgr bone_capemgr.8: slot #4: Applied #2 overlays. This behavior is not seen with Vanilla or Xenomai kernels. Reproducing this issue should be possible grabbing the rt-patched kernel and loading the overlay. There's an active discussion about this topic at https://groups.google.com/forum/#!topic/drones-discuss/7DKcdm0AEPo. Thanks for your time, Víctor Mayoral Vilches. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
