Error when fstrim: mc-err: (0) csr_afir: EMEM decode error on PDE or PTE entry

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi. I have a problem with my jetson nano with ssd.

When I run the command

sudo systemctl start fstrim

the following errors are written in the syslog:

Nov 22 09:49:17 jetson systemd[1]: Starting Discard unused blocks...
Nov 22 09:49:17 jetson kernel: [58317.362194] smmu_dump_pagetable(): fault_address=0x00000000ff5bb000 pa=0x0000000000000000 bytes=1000 #pte=205 in L2
Nov 22 09:49:17 jetson kernel: [58317.372697] mc-err: (0) csr_afir: EMEM decode error on PDE or PTE entry
Nov 22 09:49:17 jetson kernel: [58317.379333] mc-err:   status = 0x6000000e; addr = 0xff5bb000
Nov 22 09:49:17 jetson kernel: [58317.385011] mc-err:   secure: no, access-type: read, SMMU fault: nr-nw-s
Nov 22 09:49:17 jetson kernel: [58317.392589] smmu_dump_pagetable(): fault_address=0x00000000ff5bb000 pa=0x0000000000000000 bytes=1000 #pte=205 in L2
Nov 22 09:49:17 jetson kernel: [58317.403049] mc-err: (0) csr_afir: EMEM decode error on PDE or PTE entry
Nov 22 09:49:17 jetson kernel: [58317.409676] mc-err:   status = 0x6000000e; addr = 0xff5bb000
Nov 22 09:49:17 jetson kernel: [58317.415351] mc-err:   secure: no, access-type: read, SMMU fault: nr-nw-s
Nov 22 09:49:18 jetson fstrim[12871]: /mnt/ssd: 116.8 GiB (125426262016 bytes) trimmed
Nov 22 09:49:18 jetson fstrim[12871]: /: 2.3 GiB (2444632064 bytes) trimmed
Nov 22 09:49:18 jetson systemd[1]: Started Discard unused blocks.

Does anyone know how to fix it? Is that “dangerous” for the ssd?

Thanks!

3

Hi,
Please share more information about fstrim. We don’t have much experience about this service. And do you use latest Jetpack 4.6.2?

4

Hi,
thanks for the fast reply.

fstrim is a command which discards blocks that are no longer in use by a mounted file system. See this link for more.

I noticed it just because the error i posted before appeared some minutes after booting for the first time (in the syslog and in the terminal), I didn’t know that command before that.

It seems that this command is launched once a week from the system (by default). It shows from journalctl -u fstrim.timer output:

-- Logs begin at Mon 2022-11-21 17:37:21 CET, end at Tue 2022-11-22 09:44:11 CET. --
Nov 21 17:37:24 jetson systemd[1]: Started Discard unused blocks once a week.

Finally yes, I’m using jetpack 4.6.2.

5

Hi,
fstrim(8) - Linux manual page looks to be a command, not a service. Does it work if you directly execute the command?

6

Hi,

Yes, of course it is a command, but it seems that there is an homonym service which launch the command once a week. That’s why I noticed it, it’s executed automatically once a week.

I tried to run the command manually and it returns the same errors. But if I run it once again after a short time (seconds) everything works and no errors are returned.

Thanks!