Andreas, and all others
that means we're talking this one (have you had a look at Bugzilla #15014?
Might be useful...):
Which is too bad just because I found this approximately five minutes
*after* making the report. And then saw the kernel parameter. Well, I
afraid 8 hours of bisecting kernel sources when looking for the bug left
some traces at my concentration.... (-;
O2-bridges can do read prefetch and write burst. However, for some
combinations
of older bridges and cards, this causes problems, so it is disabled for
those
bridges. Now, as some users know their setup works with the speedups
enabled, a
new parameter is introduced to the driver. Now, a user can specifically
enable
or disable these features, while the default is what we have today: detect
the
bridge and decide accordingly. Fixes Bugzilla entry 15014.
Is the author of the *original* bug report (15014) still reachable
allowing you to make at least an educated guess as *when* to disable
prefetch & burst?
A useful idea would be to kindly ask Tomáš Kováčik (CC'd) about details of his
system
(4 years later - but hopefully...), specifically lspci -vv -xxx or some such
(especially the revision of that controller might be *different*,
so perhaps only *some* 6933 remained affected, whereas newer ones of that
possibly more modern chipset ID started to get corrected).
Or quite likely there's some sufficiently detailed lspci log of that hardware
out on the internet somewhere...
Note well that my chipset is intel, not ali.
As a matter of fact, I *may* have two other old laptops sitting around,
I would need to check which PCMCIA bridge they use. At least one of them
is from the same generation, so it's probably also an O2 6933. Will try
tomorrow...
And of course there remains the question *why* such slow communication
would then cause such severe USB HC communication trouble.
There might be some safeguard missing there as well...
It seems to me that the bridge can otherwise not keep up with the ehci
communications speed, but that's more a guess too.
Note that this is only a 1.7Ghz Pentium-4-M dinosaur.
That means you really don't want to know which kinds of machines I am using ;)
(yes, I'm sitting at a CardBus box here, too)
((TI CardBus controller))
That's from an old machine that's just good enough for sitting at my
table and playing some movies. It has radeon accelerated graphics
(remarkable for that age) and is *just* fast enough for that. Thus, no
need to throw it out. I'm rarely actively working on it, though email
and web is quite ok.
There is still a Fujitsu C1020 I could check, and a IBM R31, before they
go into the trash. If that's of any help.
What I would hope for would probably a warning when booting up the
kernel, and probably disabling ehci on it, again with a warning and a
hint for the kernel parameter. Just to avoid that others have to go
through the data loss I had when just connecting an external USB 2
harddrive.
Thanks,
Thomas
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