ath9k-htc on OHCI -> bogus usb xfer

Alexey Brodkin Alexey.Brodkin at synopsys.com
Wed Jul 6 01:45:50 PDT 2016


Hi Oleksij,

On Wed, 2016-07-06 at 10:38 +0200, fixed-term.Oleksij.Rempel wrote:
> 
> On 06.07.2016 10:32, Alexey Brodkin wrote:
> > 
> > Hi Oleksij,
> > 
> > On Wed, 2016-07-06 at 10:24 +0200, fixed-term.Oleksij.Rempel wrote:
> > > 
> > >  
> > > Hm... this Endpoint should be Interrupt, not Bulk. If you search for
> > > lsusb of this kind of adapter all of them list EP3 and EP4 as Interrupt.
> > > 
> > > what did went wrong here? Is it not working in USB High Speed mode?
> > Unfortunately as of now on that board EHCI doesn't work.
> > 
> > That's not a problem of a particular USB device but something in either
> > ECHI host controller or its integration. I do hope we will fix it sometime soon
> > (this is a development board and USB controller is implemented in FPGA so
> > there's a chance to fix stuff later on).
> > 
> > So given only OHCI works on the board I went forward and attempted to use it
> > with Wi-Fi USB dongle.
>
> I did some tests for 2 years on OHCI controller on x86. There was no
> noticable issues. It was even a bit faster then Intels EHCI. I don't
> think OHCI alone is the source of this problem.

Well I was also surprised how well that dongle works with that board in
OHCI mode. I saw quite consistent ~4-5 Mbit/second rates when doing Speedtest
from my smartphone. So IMHO it's completely usable. Especially on that kind of
HW which has main CPU running at just 100MHz.

> On other side, so far i know, this adapter claims to provide usb full
> speed support, (Not only high speed) and may use different usb
> descriptor for this. May be this is the problem.

So is there something we may do with all that?

-Alexey



More information about the linux-snps-arc mailing list