Sole splat seen during brief master usability test drive. (older rpi kernel is still way better idea, but it's improving.. boots, runs and hdmi audio started working) [ 0.007076] smp: Bringing up secondary CPUs ... [ 0.008304] Detected PIPT I-cache on CPU1 [ 0.008377] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 [ 0.008384] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 [ 0.008391] preempt_count: 1, expected: 0 [ 0.008396] RCU nest depth: 1, expected: 1 [ 0.008400] Preemption disabled at: [ 0.008403] [<ffffffd3244ca8e0>] migrate_enable+0x40/0x170 [ 0.008425] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.0.g0b1dcc2-rt4 #25 [ 0.008437] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT) [ 0.008442] Call trace: [ 0.008445] dump_backtrace.part.0+0xe8/0xf4 [ 0.008455] show_stack+0x20/0x50 [ 0.008463] dump_stack_lvl+0x64/0x80 [ 0.008477] dump_stack+0x18/0x34 [ 0.008488] __might_resched+0x15c/0x1c0 [ 0.008502] rt_spin_lock+0x38/0xd0 [ 0.008514] rmqueue_bulk+0x68/0x850 [ 0.008529] get_page_from_freelist+0xbe4/0xfa0 [ 0.008542] __alloc_pages+0x14c/0xf70 [ 0.008554] new_slab+0x2f0/0x374 [ 0.008569] ___slab_alloc+0x5f0/0xbcc [ 0.008584] __kmem_cache_alloc_node+0xd0/0x380 [ 0.008591] __kmalloc+0x6c/0x1c0 [ 0.008603] detect_cache_attributes+0x448/0x564 [ 0.008620] update_siblings_masks+0x30/0x304 [ 0.008631] store_cpu_topology+0x48/0x60 [ 0.008640] secondary_start_kernel+0xc8/0x144 [ 0.008656] __secondary_switched+0xb0/0xb4 [ 0.008752] CPU1: Booted secondary processor 0x0000000001 [0x410fd083] [ 0.010180] Detected PIPT I-cache on CPU2 [ 0.010300] CPU2: Booted secondary processor 0x0000000002 [0x410fd083] [ 0.011522] Detected PIPT I-cache on CPU3 [ 0.011649] CPU3: Booted secondary processor 0x0000000003 [0x410fd083] [ 0.011768] smp: Brought up 1 node, 4 CPUs