Re: xhci USB transaction error and subsequent recovery mechanism on Freebsd stable/12

From: Rodney W. Grimes <>
Date: Tue, 12 Apr 2022 22:56:12 UTC
> --------
> mahesh mv writes:
> > READ(10) errors. The READ(10) error recovers with in couple of retries most
> > of the times but few cases we have observed that the read retries gets exhausted and [...]
... [ large amount of good information removed ] ...

> Poul-Henning
> PS: "completed with an error" without any details about the error is not very helpful for debugging...

One of the very reasons that I keep my "disk drive debugging" work all on
a 5.4p8 system is that when things transitioned to CAM most of the useful
low level error messages disappeared as the CAM layer doesn't output
them.  IIRC we no longer get the LBA when a read defect is reported,
or we get it, but it is in the cryptic form of a dumped CCB.

It would be wonderful to get that "funtionality" back.

> -- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk@FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe    
> Never attribute to malice what can adequately be explained by incompetence.

Rod Grimes