[Q] USB is very slow. Is this a known bug?

Greg KH greg at kroah.com
Sat Sep 22 16:04:27 EDT 2012

On Sat, Sep 22, 2012 at 04:03:42PM -0300, Ezequiel Garcia wrote:
> Hello,
> Has anyone had problems with usb bandwidth?
> According to this page:
> http://elinux.org/RPi_Performance#USB_bus
> The rpi can achieve 30 Mb/s.

With a tail wind fall downhill, it maybe can get that fast.

> However, a user has reported a much lower bandwidth, as low as 2 Mb/s.
> See here:
> https://github.com/ezequielgarcia/stk1160-standalone/issues/5#issuecomment-7560214

Quite common, most USB storage devices are really really slow.  Also,
iso data is quite different for this controller, it's amazing that it
even works.

Heck, it's amazing that USB works at all on this hardware in the first
place, Just be happy you are getting _any_ data from it :)

> Is this a known bug? Has anyone seen using vanilla kernel?

You can't use a "vanilla" kernel on the rpi right now, especially for

> Are there any ideas for what might be going on?

Yes, the hardware is broken, the drivers are broken, and I would not
recommend anyone wanting to do any real USB data transfers to use this
platform at all.  Seriously.  Go complain to Broadcom if you want to see
this fixed, they are the ones with the specs that we can not get access

Good luck,

greg k-h

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