-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sunday 23 November 2003 17:02, Ged Haywood wrote:
> On Sun, 23 Nov 2003, Sean E. Russell wrote:
> > I get a string of "device not accepting ID" errors.
>
> Are you sure about that message?  Have you seen
>
> http://www.linux-usb.org/FAQ.html#ts6

Yeah; I had tried everything in that FAQ entry, and more.  I was pretty well 
convinced it was some hardware related issue due to the fact that it was 
failing on laptops from different vendors, running different Linux distros 
and different kernel versions.  Furthermore, we're heavy USB consumers -- 
cameras, printers, CF and SD card readers, mice, keyboards... you name it.

It was even more simple than that.  The device wasn't powered on.

What confused me was that the device is somehow active even when it is off.  I 
mean, the device is off, plug it in to the computer, and the errors start 
appearing in the kernel logs.  This is the first USB device I've seen that 
behaves like this, so it never occurred to me to try powering on the device 
before plugging it in.

So, now I'm really confused about how USB works.  My problem is solved, but 
I'm curious about what I'm seeing.  Before this, I figured there were only 
two possible cases:

1) The device is USB powered, in which case, it comes on and connects to the 
bus when you plug it in.
2) The device is not USB powered, in which case it only connects to the bus 
when it is turned on, either before or after the USB cable is connected.

Now I've seen a third case: the device is obviously connecting in some way to 
the bus while it is off, although it doesn't work properly, but if you power 
it on, it works fine.  I'd think that it has some mode where it *can* be 
powered by USB, and that the USB port on the laptop wasn't supplying enough 
power.  In fact, I tried connecting it through a powered USB hub, at one 
point.  However, there's enough power to run an optical mouse, a webcam, and 
a variety of USB flash card readers through any of the three ports on the 
laptop.  The laptops were plugged in to the wall during all of this, as they 
usually are.

What am I seeing?  Is this behavior "allowed", and I just haven't seen it 
before?


Ironically,  I've been lurking here for a month, and have been trying 
different solutions for about that long.  I find my own error 15 minutes 
after posting to the list.  Go figure.

- -- 
### SER   
### Deutsch|Esperanto|Francaise|Linux|XML|Java|Ruby|Aikido|Dirigibles
### http://www.germane-software.com/~ser  jabber.com:ser  ICQ:83578737 
### GPG: http://www.germane-software.com/~ser/Security/ser_public.gpg
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (GNU/Linux)

iD8DBQE/wVcEP0KxygnleI8RArbcAKCV6NiHRlmZSh5j0XWT90E4rrMnmgCeKHBw
2Ev1rEbimqc3W3zWpAGfFwI=
=N76o
-----END PGP SIGNATURE-----



-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
Does SourceForge.net help you be more productive?  Does it
help you create better code?  SHARE THE LOVE, and help us help
YOU!  Click Here: http://sourceforge.net/donate/
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-users

Reply via email to