Reported by Andreas Kemnade, May 1, 2017

suspend in 4.11-rc8 seems not to work reliably:

waking up by button seems to be a problem.
This message seems to be suspicious:
root@(none):/# modprobe gpio-twl4030
[   59.111633] twl4030_gpio twl4030-gpio: can't dispatch IRQs from 
modules


playing around with measure-suspend I just got this backtrace:

[  260.604461] PM: Preparing system for sleep (mem)
[  260.618957] Freezing user space processes ... (elapsed 0.003 
seconds) done.
[  260.630584] Freezing remaining freezable tasks ... (elapsed 0.003 
seconds) done.
[  260.641906] PM: Suspending system (mem)
[  260.674621] Unable to handle kernel NULL pointer dereference at 
virtual address 000000a0
[  260.683563] pgd = dc8a4000
[  260.686523] [000000a0] *pgd=9c88e831, *pte=00000000, 
*ppte=00000000
[  260.693145] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[  260.698822] Modules linked in: usb_f_ecm g_ether usb_f_rndis 
u_ether libcomposite configfs omap2430 twl4030_charger industrialio 
phy_twl4030_usb musb_hdrc gpio_twl4030
[  260.714569] CPU: 0 PID: 980 Comm: measure-suspend Not tainted 
4.11.0-rc8-letux+ #7
[  260.722503] Hardware name: Generic OMAP36xx (Flattened Device 
Tree)
[  260.729034] task: ddf7b100 task.stack: ddfbc000
[  260.733825] PC is at uart_suspend_port+0x40/0x1cc
[  260.738739] LR is at device_find_child+0x70/0x7c
[  260.743591] pc : [<c04cdbc4>]    lr : [<c04e39a8>]    
psr: 60010013
[  260.743591] sp : ddfbdd68  ip : 00000000  fp : c09c025e
[  260.755615] r10: c04e92f0  r9 : dda94330  r8 : c143724c
[  260.761077] r7 : c0c7e55c  r6 : c1468b90  r5 : dda94208  r4 : 
ddd1b410
[  260.767913] r3 : 00000000  r2 : 00000000  r1 : ddf7b6a0  r0 : 
00000000
[  260.774780] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  
Segment none
[  260.782257] Control: 10c5387d  Table: 9c8a4019  DAC: 00000051
[  260.788269] Process measure-suspend (pid: 980, stack limit = 
0xddfbc218)
[  260.795288] Stack: (0xddfbdd68 to 0xddfbe000)
[  260.799835] dd60:                   ddd1b410 c0c7e55c c0c7e514 
ddd1b410 ddaacc10 c1468b90
[  260.808410] dd80: c0ca88ac c143724c c0c0756c c04d2390 c04d2378 
c0c9a655 ddaacc10 c04f2c44
[  260.816955] dda0: c0755508 00000000 00000000 00000000 00000002 
c1468b90 ddaacc44 ddaacc10
[  260.825531] ddc0: 00000002 c1468b90 ddaacc44 00000002 c0c80bb0 
c0c0756c ddaaccd4 c04f39d8
[  260.834106] dde0: c1468b90 00000000 ddaacc10 c0ca8898 00000002 
c0c80bb0 c0c0756c c04f63e0
[  260.842651] de00: b04b610e 0000003c 00000001 c0caaf30 00000003 
00000000 00000003 c0c0756c
[  260.851226] de20: c143726c c0986564 c0c452c9 c1437278 c0986553 
c018f358 00000003 c0986564
[  260.859771] de40: c0c452c9 c1437278 c0986553 c0193ed8 c098651c 
ddfbde74 1ee28000 c0c452c9
[  260.868347] de60: c0ca8898 c0c0756c 00000003 c0986564 c0c452c9 
c1437278 c0986553 c0190d38
[  260.876892] de80: 00000000 c02e66d8 00000000 00000006 dc884640 
00000003 00000003 00000004
[  260.885467] dea0: dc884640 c0980a1e c1437280 00000000 00000000 
c018e1fc 00000004 00000004
[  260.894012] dec0: dc8063c0 dc884640 ddfbdf88 dc8063d0 00000051 
c02e6720 00000000 00000000
[  260.902587] dee0: 00000004 c02e659c ddb1b540 ddfbdf88 000d0408 
c01071e4 ddfbc000 c026f208
[  260.911163] df00: ddcb11fc c0184b7c 00000001 c0c452e1 ddcb11fc 
c019e33c c019e2c4 c019e65c
[  260.919708] df20: e09ce484 ddcb1090 00000000 c0272b2c 00000001 
00000000 c0270774 c0184b7c
[  260.928283] df40: ddb1b540 00000004 ddb1b540 00000004 ddb1b540 
ddfbdf88 000d0408 c0270788
[  260.936859] df60: ddb1b540 000d0408 00000004 ddb1b540 ddb1b540 
00000004 000d0408 c01071e4
[  260.945404] df80: ddfbc000 c0271420 00000000 00000000 00000004 
00000004 000d0408 b6e6fb50
[  260.953948] dfa0: 00000004 c0107040 00000004 000d0408 00000001 
000d0408 00000004 00000000
[  260.962524] dfc0: 00000004 000d0408 b6e6fb50 00000004 00000004 
00000000 000c5758 00000000
[  260.971069] dfe0: 00000000 beda7964 b6dd4c3d b6e0dcf6 40010030 
00000001 00000000 00000000
[  260.979644] [<c04cdbc4>] (uart_suspend_port) from 
[<c04d2390>] (serial_omap_suspend+0x18/0x54)
[  260.988677] [<c04d2390>] (serial_omap_suspend) from 
[<c04f2c44>] (dpm_run_callback+0x19c/0x454)
[  260.997772] [<c04f2c44>] (dpm_run_callback) from 
[<c04f39d8>] (__device_suspend+0x1cc/0x2ec)
[  261.006622] [<c04f39d8>] (__device_suspend) from 
[<c04f63e0>] (dpm_suspend+0x1e8/0x590)
[  261.015014] [<c04f63e0>] (dpm_suspend) from 
[<c018f358>] (suspend_devices_and_enter+0x64/0xf0c)
[  261.024108] [<c018f358>] (suspend_devices_and_enter) from 
[<c0190d38>] (pm_suspend+0xb38/0xd0c)
[  261.033233] [<c0190d38>] (pm_suspend) from 
[<c018e1fc>] (state_store+0xac/0xcc)
[  261.040893] [<c018e1fc>] (state_store) from 
[<c02e6720>] (kernfs_fop_write+0x184/0x1c0)
[  261.049285] [<c02e6720>] (kernfs_fop_write) from 
[<c026f208>] (__vfs_write+0x20/0x108)
[  261.057586] [<c026f208>] (__vfs_write) from 
[<c0270788>] (vfs_write+0xb8/0x144)
[  261.065277] [<c0270788>] (vfs_write) from 
[<c0271420>] (SyS_write+0x40/0x80)
[  261.072662] [<c0271420>] (SyS_write) from 
[<c0107040>] (ret_fast_syscall+0x0/0x1c)
[  261.080627] Code: e59400e4 e59f2184 e1a0100d eb00575c (e5d030a0) 
[  261.087127] ---[ end trace 3404fdb75d11dfae ]---