Re: USB regression in 10.1

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Fri, 24 Jan 2025 23:56:08 -0000 (UTC)
    From:        mlelstv%serpens.de@localhost (Michael van Elst)
    Message-ID:  <vn19an$b22$1%serpens.de@localhost>

  | When a disk attaches offline, the wedge discovery routine
  | previously failed and reported errors.

It did, yes - would have been nicer to suppress the error message
for such an ordinary event, but aside from the noise, it was harmless.

  | Now it is simply skipped with the same result.

Not quite the same - previously once the drive was ready, wedge
discovery would happen - not just "a few milliseconds" but up
to many seconds later in some cases (depending upon the drive).

I have never looked to see the mechanism by which that worked,
I always assumed that the drive sent some form of "now ready"
message/interrupt when it became ready, but some form of polling
from the kernel might also have been a possibility.

I also don't know whether it depended upon the drive (though I
have quite a few quite different types, and all acted the same in
this regard) or the particular controller chip (less variety of
those in my system).

kre