Hi, we're seeing the below splat in our testing of linux-next. Disassembling Code: gives 17: 90 nop 18: f3 0f 1e fa endbr64 1c: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 21: 55 push %rbp 22: 48 89 e5 mov %rsp,%rbp 25: 41 55 push %r13 27: 41 54 push %r12 29: 53 push %rbx 2a:* 8b 87 fc 01 00 00 mov 0x1fc(%rdi),%eax <-- trapping instruction which is regmap_read: endbr64 1: call __fentry__ .section __mcount_loc, "a",@progbits .quad 1b .previous pushq %rbp # movq %rsp, %rbp #, pushq %r13 # pushq %r12 # pushq %rbx # # drivers/base/regmap/regmap.c:2826: if (!IS_ALIGNED(reg, map->reg_stride)) movl 508(%rdi), %eax # map_12(D)->reg_stride, tmp107 ^^^^^^^^ i.e., that @map argument is 0. Looking at the call stack, I see 2409205acd3c ("i2c: designware: fix __i2c_dw_disable() in case master is holding SCL low") which does that dev->map deref in __i2c_dw_disable() but maybe ->map is invalid by then...? Just a stab in the dark anyway... Thx. [ 6.245173] i2c_designware AMDI0010:00: Unknown Synopsys component type: 0xffffffff [ 6.252683] BUG: kernel NULL pointer dereference, address: 00000000000001fc [ 6.256551] #PF: supervisor read access in kernel mode [ 6.256551] #PF: error_code(0x0000) - not-present page [ 6.256551] PGD 0 [ 6.256551] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 6.256551] CPU: 32 PID: 211 Comm: kworker/32:0 Not tainted 6.7.0-rc6-next-20231222-1703820640818 #1 [ 6.256551] Workqueue: pm pm_runtime_work [ 6.256551] RIP: 0010:regmap_read+0x12/0x70 [ 6.256551] Code: 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 <8b> 87 fc 01 00 00 83 e8 01 85 f0 75 42 48 89 fb 41 89 f4 49 89 d5 [ 6.256551] RSP: 0018:ff7fa5c740bcbc98 EFLAGS: 00010246 [ 6.256551] RAX: 0000000000000000 RBX: ff38ff5c159f1028 RCX: 0000000000000008 [ 6.256551] RDX: ff7fa5c740bcbcc4 RSI: 0000000000000034 RDI: 0000000000000000 [ 6.256551] RBP: ff7fa5c740bcbcb0 R08: ff38ff5c02ceb8b0 R09: ff38ff5c002a4500 [ 6.256551] R10: 0000000000000003 R11: 0000000000000003 R12: ff38ff5c159f1028 [ 6.256551] R13: 0000000000000000 R14: 0000000000000000 R15: ff38ff5c159ed8f4 [ 6.256551] FS: 0000000000000000(0000) GS:ff38ff6b0d200000(0000) knlGS:0000000000000000 [ 6.256551] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.256551] CR2: 00000000000001fc CR3: 000000007403c001 CR4: 0000000000771ef0 [ 6.256551] PKRU: 55555554 [ 6.256551] Call Trace: [ 6.256551] <TASK> [ 6.256551] ? show_regs+0x6d/0x80 [ 6.256551] ? __die+0x29/0x70 [ 6.256551] ? page_fault_oops+0x153/0x4a0 [ 6.256551] ? do_user_addr_fault+0x30f/0x6c0 [ 6.256551] ? exc_page_fault+0x7c/0x190 [ 6.256551] ? asm_exc_page_fault+0x2b/0x30 [ 6.256551] ? regmap_read+0x12/0x70 [ 6.256551] ? update_load_avg+0x82/0x7d0 [ 6.256551] __i2c_dw_disable+0x38/0x180 [ 6.256551] i2c_dw_disable+0x3f/0xb0 [ 6.256551] i2c_dw_runtime_suspend+0x33/0x50 [ 6.256551] ? __pfx_pm_generic_runtime_suspend+0x10/0x10 [ 6.256551] pm_generic_runtime_suspend+0x2f/0x40 [ 6.256551] __rpm_callback+0x48/0x120 [ 6.256551] ? __pfx_pm_generic_runtime_suspend+0x10/0x10 [ 6.256551] rpm_callback+0x66/0x70 [ 6.256551] ? __pfx_pm_generic_runtime_suspend+0x10/0x10 [ 6.256551] rpm_suspend+0x166/0x700 [ 6.256551] ? srso_alias_return_thunk+0x5/0xfbef5 [ 6.256551] ? __schedule+0x3df/0x1720 [ 6.256551] pm_runtime_work+0xb2/0xd0 [ 6.256551] process_one_work+0x178/0x350 [ 6.256551] worker_thread+0x2f5/0x420 [ 6.256551] ? __pfx_worker_thread+0x10/0x10 [ 6.256551] kthread+0xf5/0x130 [ 6.256551] ? __pfx_kthread+0x10/0x10 [ 6.256551] ret_from_fork+0x3d/0x60 [ 6.256551] ? __pfx_kthread+0x10/0x10 [ 6.256551] ret_from_fork_asm+0x1a/0x30 [ 6.256551] </TASK> [ 6.256551] Modules linked in: [ 6.256551] CR2: 00000000000001fc [ 6.256551] ---[ end trace 0000000000000000 ]--- [ 6.256551] RIP: 0010:regmap_read+0x12/0x70 [ 6.256551] Code: 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 <8b> 87 fc 01 00 00 83 e8 01 85 f0 75 42 48 89 fb 41 89 f4 49 89 d5 [ 6.256551] RSP: 0018:ff7fa5c740bcbc98 EFLAGS: 00010246 [ 6.256551] RAX: 0000000000000000 RBX: ff38ff5c159f1028 RCX: 0000000000000008 [ 6.256551] RDX: ff7fa5c740bcbcc4 RSI: 0000000000000034 RDI: 0000000000000000 [ 6.256551] RBP: ff7fa5c740bcbcb0 R08: ff38ff5c02ceb8b0 R09: ff38ff5c002a4500 [ 6.256551] R10: 0000000000000003 R11: 0000000000000003 R12: ff38ff5c159f1028 [ 6.256551] R13: 0000000000000000 R14: 0000000000000000 R15: ff38ff5c159ed8f4 [ 6.256551] FS: 0000000000000000(0000) GS:ff38ff6b0d200000(0000) knlGS:0000000000000000 [ 6.256551] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.256551] CR2: 00000000000001fc CR3: 000000007403c001 CR4: 0000000000771ef0 [ 6.256551] PKRU: 55555554 [ 6.256551] note: kworker/32:0[211] exited with irqs disabled -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette