Re: xhci USB transaction error and subsequent recovery mechanism on Freebsd stable/12
- In reply to: mahesh mv : "xhci USB transaction error and subsequent recovery mechanism on Freebsd stable/12"
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Date: Tue, 12 Apr 2022 23:04:20 UTC
On Apr 12, 2022, at 8:10 AM, mahesh mv <maheshm_v@yahoo.com> wrote: > > This issue was never observed with Linux kernel 5.4.2 on the same HW. On an external SSD I have, Linux was using UAS (USB Attached SCSI), while FreeBSD used the older BOT (Bulk Only Transport) protocol. See if your disk supports both. You can try usbconfig -d genN.M dump_all_desc # N = unit, M=device index to dump all the descriptors and see what all it supports. You should see something like this: # !! | grep Protocol bDeviceProtocol = 0x0000 bInterfaceProtocol = 0x0050 -- BOT bInterfaceProtocol = 0x0062 -- UAS Likely a remote possibility but could it be that it has a bug in the disk's BOT implementation? At any rate you can check if anyone else with the exact disk model has similar issues. Alternately, see if the problem disappears with a different disk. Another thing to check is whether the disk has any updated firmware. Note: I am not a USB expert so apologies in advance if this leads you astray! My main point being that the issue may not necessarily be a FreeBSD bug. Do share the USB traces.