[PATCH] usb: ehci: make HC see up-to-date qh/qtd descriptor ASAP

[Mark Salter]

On Wed, 2011-08-31 at 09:49 +0100, Will Deacon wrote:
> On Wed, Aug 31, 2011 at 01:23:47AM +0100, Chen Peter-B29397 wrote:
> > One question: why this write buffer issue did not happen at UP ARM V7 platform, whose dma buffer
> > also uncache, but bufferable?
> 
> Which CPU was on this platform?

Using a 3.1.0-rc4+ kernel on a Pandaboard, and running 'hdparm -t' on a
usb disk drive, I see ~5.8MB/s read speed. Same kernel, but passing
nosmp on the commandline, I see 20.3MB/s.

Can someone explain why nosmp would make such a difference?

--Mark