[U-Boot] [PATCH] usb: fix usb start problem with SMSC USB hub and Toshiba USB stick

Detlev Zundel
2010-09-24T09:41:05Z

Hi Roland,

[...]

> I have tried a third usb2ide adapter cable of different brand.
> Had that around at work....
>
> Apparently , it uses exactly the same jmicron chipset as one of the
> other ones which fail - but this one - surprise - WORKS !

Just as an additional datapoint - we have also seen usb sticks which
by all available markings looked to contain the exact same silicon.
Only persistent questioning of the manufacturer in the end showed that
"harmless changes" were done and were deemed not important enough to be
marked by changing serial-numbers or other visible identification.

> The output of "usb info" is exactly the same. Where the former one
> fails with "usb part" , this one works with "usb part" and gives proper
> info and i can boot without a problem. Loading kernel & initrd is slow,
> but it works, even with cold boot.
>
> So, i`m wondering who`s to blame - the cable or the sofware, or both :)

I still blame the inventors of USB. One of them is even depicted as a
rock star in an Intel ad - ugh. I wonder what a short film with some
actual USB developers would look like :)

> Since both cables work with linux, maybe there is some slight differenc
> in pcb/cable design and thus some slight timing difference which causing
> this problem.
>
> Maybe i will go to find some more convertor cables, just for curiousity
> and to see how they behave. Does someone know a website listing usb
> convertor cables and compare their "quality" ? I did not find such....

Did you try http://www.qbik.ch/usb/devices/ ?

> Anyway, so my problem is not that serious anymore, as i know the
> hardware is part of the problem and which can be replaced.....

See, that's another reason why we still have such problems - once a
hardware replacement is found, the problem is no longer pursued.

Note that this is a not meant as a criticism, but simply as an
explanation of the current state of affairs - I've seen this multiple
times now.

Cheers
Detlev

[1] http://www.shoppingblog.com/blog/517099

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