Comment 0 for bug 1785715

Maybe similar to Bug 1678184
Im working on ubuntu 18.04 (with Kernel 4.15.0-29-generic) on a dell XPS 15-9560
After 20 - 180 Minutes the graphical interface hangs up (i can switch workspaces, but not much else) and entering commands like "ls" yields bash: input/output error
Reboot is impossible via the command or the button. Short click on power button gives me a TTY like view prompting errors for nvme0 ext4 file system errors (i will post more exact text on next hangup)

The hangups appear randomly, but often during shutting the lid or plugging in power cable, which makes me thing it might be something with ssd power states.
For that reason i added grub parameters like "nvme_core.default_ps_max_latency_us=3000" (see Bug 1678184) and ended up fully disabling APST by setting it to 0, but the bug still occured.

sudo nvme id-ctrl /dev/nvme0 yields:
NVME Identify Controller:
vid : 0x1c5c
ssvid : 0x1c5c
sn : EJ75N621210105PBR
mn : PC300 NVMe SK hynix 1TB
fr : 20005A00
rab : 1
ieee : ace42e
cmic : 0
mdts : 5
cntlid : 0
ver : 10200
rtd3r : 90f560
rtd3e : ea60
oaes : 0
ctratt : 0
oacs : 0x16
acl : 3
aerl : 3
frmw : 0x16
lpa : 0x2
elpe : 254
npss : 4
avscc : 0x1
apsta : 0x1
wctemp : 361
cctemp : 363
mtfa : 0
hmpre : 0
hmmin : 0
tnvmcap : 0
unvmcap : 0
rpmbs : 0
edstt : 60
dsto : 1
fwug : 0
kas : 0
hctma : 0
mntmt : 0
mxtmt : 0
sanicap : 0
hmminds : 0
hmmaxd : 0
sqes : 0x66
cqes : 0x44
maxcmd : 0
nn : 1
oncs : 0x1e
fuses : 0
fna : 0
vwc : 0x1
awun : 255
awupf : 0
nvscc : 1
acwu : 0
sgls : 0
subnqn :
ioccsz : 0
iorcsz : 0
icdoff : 0
ctrattr : 0
msdbd : 0
ps 0 : mp:5.87W operational enlat:5 exlat:5 rrt:0 rrl:0
          rwt:0 rwl:0 idle_power:- active_power:-
ps 1 : mp:2.40W operational enlat:30 exlat:30 rrt:1 rrl:1
          rwt:1 rwl:1 idle_power:- active_power:-
ps 2 : mp:1.90W operational enlat:100 exlat:100 rrt:2 rrl:2
          rwt:2 rwl:2 idle_power:- active_power:-
ps 3 : mp:0.1000W non-operational enlat:1000 exlat:1000 rrt:3 rrl:3
          rwt:3 rwl:3 idle_power:- active_power:-
ps 4 : mp:0.0060W non-operational enlat:1000 exlat:5000 rrt:3 rrl:3
          rwt:3 rwl:3 idle_power:- active_power:-

sudo nvme get-feature -f 0x0c -H /dev/nvme0 yields:
get-feature:0xc (Autonomous Power State Transition), Current value:00000000
 Autonomous Power State Transition Enable (APSTE): Disabled
 Auto PST Entries .................
 Entry[ 0]
 .................
 Idle Time Prior to Transition (ITPT): 0 ms
 Idle Transition Power State (ITPS): 0
 .................
 Entry[ 1]
 .................
 Idle Time Prior to Transition (ITPT): 0 ms
 Idle Transition Power State (ITPS): 0
 ... and so on ...