Re: usb detecting only high speed devices only - not detecting low speed devices

[David Brownell <david-b@pacbell.net>]

On Monday 03 March 2008, mahendra varman wrote:
> >
> >  Now as to *why* that happens, I don't know.  We've certainly had folk
> >  using Philips/NXP EHCI controllers successfully before.  Maybe this
> >  board has a hardware problem, like a bad chip or not having wired
> >  up the power lines that OHCI controller uses.
> 
> still the low speed devices are giving unlink after no IRQ.. 

Not at all surprising if you haven't changed anything.

You *did* verify this happens on all the ports of that chip?


> My 
> hardware engineer says he followed the reference schematics of ISP1562
> of philips. He says that ohci side, the power lines are wired up
> 
> My Ehci devices can be mounted and the files are read
> Today I faced another issue
> For some usb ehci devices its giving "device descriptor read/64, error
> -71" ( for some usb stick of usb2.0)
> but for others i can able to mount without this error.....
> 
> Sir, Any clue regarding the above problem iam facing currently ??

I gave you all the clues I've got.  You're the one with the
uniquely mis-behaving hardware...

Time for you to work harder at debugging your problem.  You
have the hardware, the software source code, a cooperative
hardware engineer ... that's a lot more than most folk have
when they start to chase down problems like this.

- Dave