Bug 208647

Summary: persistent amdgpu: [mmhub] page faults
Product: Drivers Reporter: Jay Foad (jay.foad)
Component: Video(DRI - non Intel)Assignee: drivers_video-dri
Status: NEW ---    
Severity: normal CC: alexdeucher, mail, nhaehnle
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 5.4.0-42-generic Subsystem:
Regression: No Bisected commit-id:
Attachments: output of journalctl -b-5 -k
dmesg on 5.9.0-RC7

Description Jay Foad 2020-07-21 14:35:45 UTC 
Whenever X is running I get persistent page faults like this:

Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu: [mmhub] page fault (src_id:0 ring:169 vmid:0 pasid:0, for process  pid 0 thread  pid 0)
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:   in page starting at address 0x00000000fffb0000 from client 18
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu: GCVM_L2_PROTECTION_FAULT_STATUS:0x00041F52
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:          Faulty UTCL2 client ID: 0xf
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:          MORE_FAULTS: 0x0
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:          WALKER_ERROR: 0x1
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:          PERMISSION_FAULTS: 0x5
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:          MAPPING_ERROR: 0x1
Jul 21 15:19:16 jay-X470-AORUS-ULTRA-GAMING kernel: amdgpu 0000:0c:00.0: amdgpu:          RW: 0x1

Sometimes I get several of these per second. Sometimes there are none for a few minutes.

If I boot into runlevel 3 (i.e. without starting X) I get one of these during boot, but then there are no more after that.

I'm running Ubuntu 20.04 but I also saw this on 18.04.

Kernel version is 5.4.0-42-generic but I also saw this with 5.3.0-51-generic.

I'm using the amdgpu-pro drivers.

Graphics card is a Navi 10.

Motherboard is a Gigabyte X470 AORUS ULTRA GAMING.

CPU is an AMD Ryzen 9 3900X.

A very similar sounding bug was reported here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1888116
Comment 1 Alex Deucher 2020-07-21 15:13:14 UTC 
This is most likely a userspace issue (e.g., mesa).  The kernel driver is just the messenger.
Comment 2 Jay Foad 2020-07-21 15:15:07 UTC 
Wouldn't there normally be a useful pid in the first line if it came from userspace?
Comment 3 Nicolai Hähnle 2020-07-21 15:22:12 UTC 
Hi Alex, I asked Jay to report this because (1) the fact that there's a fault during boot is suspicious and points in the direction of this being the kernel's fault and (2) the fact that it's an *mmhub* fault is even more suspicious.

Certainly this seems to happen without Mesa video encode/decode activity, so it can't really be Mesa's (or any graphics driver's) fault.

Someone suggested that audio support also goes through mmhub and that it may be related. I have no idea if that's true.
Comment 4 Alex Deucher 2020-07-21 15:26:44 UTC 
Please attach your full dmesg output and xorg log (if using X).
Comment 5 Jay Foad 2020-07-21 15:34:06 UTC 
Created attachment 290439 [details]
output of journalctl -b-5 -k
Comment 6 Stefan Winter 2020-09-28 15:17:29 UTC 
FWIW, this still (or again) happens with a 5.9.0-RC7 with a Navi 10. It did not happen on 5.8.6 with slightly different .config though.

Attaching a full dmesg. Note that the page faults start happening very shortly after the snd_hda_intel initialization which activates amdgpu.
Comment 7 Stefan Winter 2020-09-28 15:18:23 UTC 
Created attachment 292697 [details]
dmesg on 5.9.0-RC7

dmesg