I have a small SPI LCD that I recently attached and configured on an RPi Zero, and when I saw this post my curiosity got the better of me and I attached it to my OPi PC+ using the fbtft drivers.
OS: Ubuntu 16.04 xenial
Linux orangepipcplus 3.4.113-sun8i #4 SMP PREEMPT Wed Nov 22 13:45:28 CET 2017 armv7l armv7l armv7l GNU/Linux
Sadly, i can report the same issue on my system. It worked faultlessly for about 30 minutes, then crashed in the exact same manner:
[ 1800.550427] INFO: task kworker/0:2:71 blocked for more than 120 seconds.
[ 1800.550436] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1800.550447] kworker/0:2 D c061d264 0 71 2 0x00000000
[ 1800.550474] [<c061d264>] (__schedule+0x574/0x7fc) from [<c061d57c>] (schedule+0x90/0x94)
[ 1800.550495] [<c061d57c>] (schedule+0x90/0x94) from [<c061b4bc>] (schedule_timeout+0x2c/0x2bc)
[ 1800.550517] [<c061b4bc>] (schedule_timeout+0x2c/0x2bc) from [<c061ca58>] (wait_for_common+0x120/0x168)
[ 1800.550539] [<c061ca58>] (wait_for_common+0x120/0x168) from [<c061cac0>] (wait_for_completion+0x20/0x24)
[ 1800.550561] [<c061cac0>] (wait_for_completion+0x20/0x24) from [<c03e6384>] (spi_sync+0x84/0xa0)
[ 1800.550601] [<c03e6384>] (spi_sync+0x84/0xa0) from [<bf2be34c>] (fbtft_write_spi+0xf0/0x104 [fbtft])
[ 1800.550643] [<bf2be34c>] (fbtft_write_spi+0xf0/0x104 [fbtft]) from [<bf2be208>] (fbtft_write_vmem16_bus8+0x11c/0x138 [fbtft])
[ 1800.550682] [<bf2be208>] (fbtft_write_vmem16_bus8+0x11c/0x138 [fbtft]) from [<bf2bb918>] (fbtft_update_display+0x150/0x2fc [fbtft])
[ 1800.550720] [<bf2bb918>] (fbtft_update_display+0x150/0x2fc [fbtft]) from [<bf2bb2a8>] (fbtft_deferred_io+0x110/0x11c [fbtft])
[ 1800.550752] [<bf2bb2a8>] (fbtft_deferred_io+0x110/0x11c [fbtft]) from [<c03886cc>] (fb_deferred_io_work+0x84/0xcc)
[ 1800.550777] [<c03886cc>] (fb_deferred_io_work+0x84/0xcc) from [<c0044660>] (process_one_work+0x248/0x404)
[ 1800.550799] [<c0044660>] (process_one_work+0x248/0x404) from [<c0045a98>] (worker_thread+0x1b4/0x2d0)
[ 1800.550820] [<c0045a98>] (worker_thread+0x1b4/0x2d0) from [<c0049db0>] (kthread+0x94/0xa0)
[ 1800.550843] [<c0049db0>] (kthread+0x94/0xa0) from [<c000f270>] (kernel_thread_exit+0x0/0x8)
