Re: [linux-usb-devel] Genesys USB 2.0 enclosures

[Matthew Dharm <mdharm-kernel@one-eyed-alien.net>]

[-- Attachment #1: Type: text/plain, Size: 1409 bytes --]

On Sat, Sep 03, 2005 at 09:53:19PM -0400, Alan Stern wrote:
> On Sat, 3 Sep 2005, Jan De Luyck wrote:
> 
> > I've posted in the past about problems with these enclosures - increasing the 
> > delay seems to fix it, albeit temporarily. The further you go in using the 
> > disk in such an enclosure, the higher the udelay() had to be - atleast that's 
> > what I'm seeing here (I've got two of these now :/ )
> > 
> > One permanent fix is adding a powered USB-hub in between the drive enclosures 
> > and the computer. Since I've done that, I've no longer seen any of the 
> > problems (i've attached the 'fault' log). Weird but true, since the drives 
> > come with their own powersupply.
> > 
> > Hope this helps anyone in the future running into the same problem.
> 
> This one certainly goes into the Bizarro file.
> 
> Just out of curiosity -- when you use the powered hub, does the drive work 
> even if you remove that delay completely?

Aren't USB 2.0 hubs more "intelligent" as part of the requirement to
support 1.1 and 2.0 devices?  I wonder if it's really a 2.0 drive, and if
the timing is different enough with the hub to make a difference.

Matt

-- 
Matthew Dharm                              Home: mdharm-usb@one-eyed-alien.net 
Maintainer, Linux USB Mass Storage Driver

THEY CASTRATED MY QUAKE BITS! I WANT THEM BACK!!!!
					-- Greg
User Friendly, 3/27/1998

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]