Resolved MacPro 5,1 freezing when running Ubuntu 22.04

[cliverlong]

I have recently installed Linux Ubuntu on an SSD attached to MacPro 5,1 via a USB caddy and USB 3 card in a PCIe slot. The OS boots fine but randomly the machine freezes then pops up a window that asks if I wish to wait for an application or force quit. This freeze can happen on any active application (Chrome, textedit) and there doesn't seem to be a pattern to the freezing. Eventually the machine will resume processing then freeze at some later time. I have a copy of the syslog but I don't know what to look for. The start and end of the current syslog for this boot look as follows:

Nov 10 10:34:26 MacPro-Linux systemd-modules-load[288]: Inserted module 'lp'
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] microcode: microcode updated early to revision 0x1f, date = 2018-05-08
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] Linux version 6.2.0-36-generic (buildd@lcy02-amd64-050) (x86_64-linux-gnu-gcc-11 (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0, GNU ld (GNU Binutils for Ubuntu) 2.38) #37~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon Oct 9 15:34:04 UTC 2 (Ubuntu 6.2.0-36.37~22.04.1-generic 6.2.16)
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] Command line: initrd=\boot\initrd.img-6.2.0-36-generic root=PARTUUID=57424c9d-aa38-49cf-b5a7-90b1707f6c07 ro quiet splash
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] KERNEL supported cpus:
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] Intel GenuineIntel
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] AMD AuthenticAMD
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] Hygon HygonGenuine
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] Centaur CentaurHauls
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] zhaoxin Shanghai
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] Disabled fast string operations
Nov 10 10:34:26 MacPro-Linux kernel: [ 0.000000] BIOS-provided physical RAM map:


......

Nov 10 13:45:01 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134501.499168:ERROR:gbm_wrapper.cc(253)] Failed to export buffer to dma_buf: No such file or directory (2)
Nov 10 13:45:01 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134501.499305:ERROR:gbm_wrapper.cc(253)] Failed to export buffer to dma_buf: No such file or directory (2)
Nov 10 13:45:01 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134501.499465:ERROR:gbm_wrapper.cc(253)] Failed to export buffer to dma_buf: No such file or directory (2)
Nov 10 13:45:01 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134501.499594:ERROR:gbm_wrapper.cc(253)] Failed to export buffer to dma_buf: No such file or directory (2)
Nov 10 13:45:01 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134501.499738:ERROR:gbm_wrapper.cc(253)] Failed to export buffer to dma_buf: No such file or directory (2)
Nov 10 13:45:01 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134501.499902:ERROR:gbm_wrapper.cc(253)] Failed to export buffer to dma_buf: No such file or directory (2)
Nov 10 13:46:41 MacPro-Linux kernel: [11544.477739] sd 6:0:0:0: [sdb] tag#21 uas_eh_abort_handler 0 uas-tag 7 inflight: CMD OUT
Nov 10 13:46:41 MacPro-Linux kernel: [11544.477750] sd 6:0:0:0: [sdb] tag#21 CDB: Write(10) 2a 00 10 48 d2 00 00 01 10 00
Nov 10 13:46:41 MacPro-Linux kernel: [11544.583986] sd 6:0:0:0: [sdb] tag#16 uas_eh_abort_handler 0 uas-tag 5 inflight: CMD OUT
Nov 10 13:46:41 MacPro-Linux kernel: [11544.583994] sd 6:0:0:0: [sdb] tag#16 CDB: Write(10) 2a 00 02 75 81 e0 00 00 10 00
Nov 10 13:46:41 MacPro-Linux kernel: [11544.695972] sd 6:0:0:0: [sdb] tag#15 uas_eh_abort_handler 0 uas-tag 4 inflight: CMD OUT
Nov 10 13:46:41 MacPro-Linux kernel: [11544.695980] sd 6:0:0:0: [sdb] tag#15 CDB: Write(10) 2a 00 10 48 6a d0 00 00 a0 00
Nov 10 13:46:42 MacPro-Linux kernel: [11544.807950] sd 6:0:0:0: [sdb] tag#14 uas_eh_abort_handler 0 uas-tag 3 inflight: CMD OUT
Nov 10 13:46:42 MacPro-Linux kernel: [11544.807958] sd 6:0:0:0: [sdb] tag#14 CDB: Write(10) 2a 00 10 48 66 d0 00 04 00 00
Nov 10 13:46:42 MacPro-Linux kernel: [11544.919955] sd 6:0:0:0: [sdb] tag#13 uas_eh_abort_handler 0 uas-tag 2 inflight: CMD OUT
Nov 10 13:46:42 MacPro-Linux kernel: [11544.919963] sd 6:0:0:0: [sdb] tag#13 CDB: Write(10) 2a 00 10 48 63 e0 00 02 f0 00
Nov 10 13:46:42 MacPro-Linux kernel: [11545.031898] sd 6:0:0:0: [sdb] tag#12 uas_eh_abort_handler 0 uas-tag 1 inflight: CMD OUT
Nov 10 13:46:42 MacPro-Linux kernel: [11545.031906] sd 6:0:0:0: [sdb] tag#12 CDB: Write(10) 2a 00 10 48 5f e0 00 04 00 00
Nov 10 13:46:42 MacPro-Linux kernel: [11545.143874] sd 6:0:0:0: [sdb] tag#2 uas_eh_abort_handler 0 uas-tag 6 inflight: CMD OUT
Nov 10 13:46:42 MacPro-Linux kernel: [11545.143881] sd 6:0:0:0: [sdb] tag#2 CDB: Write(10) 2a 00 10 48 25 00 00 00 b0 00
Nov 10 13:46:42 MacPro-Linux kernel: [11545.144017] sd 6:0:0:0: [sdb] tag#17 uas_eh_abort_handler 0 uas-tag 8 inflight: CMD OUT
Nov 10 13:46:42 MacPro-Linux kernel: [11545.144023] sd 6:0:0:0: [sdb] tag#17 CDB: Write(10) 2a 00 10 48 cc 28 00 00 30 00
Nov 10 13:46:43 MacPro-Linux kernel: [11545.821574] sd 6:0:0:0: [sdb] tag#22 uas_eh_abort_handler 0 uas-tag 11 inflight: CMD OUT
Nov 10 13:46:43 MacPro-Linux kernel: [11545.821582] sd 6:0:0:0: [sdb] tag#22 CDB: Write(10) 2a 00 10 49 0d 48 00 00 18 00
Nov 10 13:46:43 MacPro-Linux kernel: [11545.821714] sd 6:0:0:0: [sdb] tag#19 uas_eh_abort_handler 0 uas-tag 10 inflight: CMD OUT
Nov 10 13:46:43 MacPro-Linux kernel: [11545.821720] sd 6:0:0:0: [sdb] tag#19 CDB: Write(10) 2a 00 10 49 0d 00 00 00 28 00
Nov 10 13:46:43 MacPro-Linux kernel: [11545.821857] sd 6:0:0:0: [sdb] tag#18 uas_eh_abort_handler 0 uas-tag 9 inflight: CMD OUT
Nov 10 13:46:43 MacPro-Linux kernel: [11545.821862] sd 6:0:0:0: [sdb] tag#18 CDB: Write(10) 2a 00 10 49 0c c8 00 00 18 00
Nov 10 13:46:43 MacPro-Linux kernel: [11545.837550] scsi host6: uas_eh_device_reset_handler start
Nov 10 13:46:43 MacPro-Linux kernel: [11545.966020] usb 10-1: reset SuperSpeed USB device number 2 using xhci_hcd
Nov 10 13:46:43 MacPro-Linux kernel: [11545.987917] scsi host6: uas_eh_device_reset_handler success
Nov 10 13:47:14 MacPro-Linux kernel: [11577.245554] scsi host6: uas_eh_device_reset_handler start
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681589] sd 6:0:0:0: [sdb] tag#0 uas_zap_pending 0 uas-tag 8 inflight: CMD
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681598] sd 6:0:0:0: [sdb] tag#0 CDB: Write(10) 2a 00 10 48 66 d0 00 04 00 00
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681603] sd 6:0:0:0: [sdb] tag#1 uas_zap_pending 0 uas-tag 9 inflight: CMD
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681606] sd 6:0:0:0: [sdb] tag#1 CDB: Write(10) 2a 00 10 48 6a d0 00 00 a0 00
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681610] sd 6:0:0:0: [sdb] tag#2 uas_zap_pending 0 uas-tag 10 inflight: CMD
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681613] sd 6:0:0:0: [sdb] tag#2 CDB: Write(10) 2a 00 02 75 81 e0 00 00 10 00
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681617] sd 6:0:0:0: [sdb] tag#4 uas_zap_pending 0 uas-tag 11 inflight: CMD
Nov 10 13:47:14 MacPro-Linux kernel: [11577.681620] sd 6:0:0:0: [sdb] tag#4 CDB: Write(10) 2a 00 10 48 d2 00 00 01 10 00
Nov 10 13:47:15 MacPro-Linux kernel: [11577.809900] usb 10-1: reset SuperSpeed USB device number 2 using xhci_hcd
Nov 10 13:47:15 MacPro-Linux kernel: [11577.831328] scsi host6: uas_eh_device_reset_handler success
Nov 10 13:47:15 MacPro-Linux google-chrome.desktop[14594]: [14587:14587:1110/134715.455389:ERROR:event_ack_data.cc(47)] StartExternalRequest failed: 2
Nov 10 13:47:15 MacPro-Linux google-chrome.desktop[14594]: [14587:14587:1110/134715.457998:ERROR:event_ack_data.cc(47)] StartExternalRequest failed: 2
Nov 10 13:47:15 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134715.505205:ERROR:shared_image_manager.cc(220)] SharedImageManager:roduceSkia: Trying to Produce a Skia representation from a non-existent mailbox.
Nov 10 13:47:15 MacPro-Linux google-chrome.desktop[14594]: [14633:14633:1110/134715.505537:ERROR:shared_image_manager.cc(220)] SharedImageManager:roduceSkia: Trying to Produce a Skia representation from a non-existent mailbox.


Any suggestions on what to look for to try to locate the problem?

The MP5,1 machine boots and operates fine on Monterey and Ventura helped by OpenCore / OCLP.

Regards.

 

[cliverlong]

I moved the Linux drive from the USB 3 caddy and USB 3 PCIe card to an internal bay using a 2.5 inch to 3.5 inch adapter and the boot process to Linux s more responsive and I see the wait dialog much less often. I did a disk speed test with the SSD attached via USB 3 and internally (SATA?) and both reported about 290 MBps. However, maybe the USB 3 card somehow gets "overloaded" when trying to support an OS disk.