Re: Firewire/USB Card for Qube 2

[Evgueni Tzvetanov <attroppa%yahoo.com@localhost>]

--- Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost> wrote:

> I wrote:
> 
> > But current EHCI/UHCI/OHCH drivers completely lack
> > bus_dmamap_sync(9) calls so there might be DMA
> cache
> > coherent problem on heavy load.
> 
> Okay, I got the errors after some load:
> 
> umass0: BBB reset failed, TIMEOUT
> umass0: BBB bulk-in clear stall failed, TIMEOUT
> 
> Maybe we should wait itohy-usb1 branch (which aims
> "USB stack overhaul, mostly DMA related") merge...
> ---
> Izumi Tsutsui
> 

My guess would be also from performance point of view
with no DMA the USB will not take up to the desired
speeds, but also the CPU will be screwed, because on
large transfers it has to work hard, but after all it
is just a MIPS old workhorse.