[Qemu-devel] Re: [patch 2/2] support for UHCI suspend / remote wake up

[Marcelo Tosatti]

On Wed, Dec 01, 2010 at 04:12:14PM +0100, Gerd Hoffmann wrote:
> On 11/25/10 18:04, Marcelo Tosatti wrote:
> >This patch enables USB UHCI global suspend/resume feature. The OS will
> >stop the HC once all ports are suspended. If there is activity on the
> >port(s), an interrupt signalling remote wakeup will be triggered.
> >
> >To enable autosuspend for the USB tablet on Linux guests:
> >
> >echo auto>  /sys/devices/pci0000:00/0000:00:01.2/usb1/1-1/power/level
> 
> Hmm, did you ever got this working sanely?

Yes. Linux and Windows.

> /me sees bus disconnects in the guest ...

I was seeing bus disconnects when not clearing port resume bit properly.

> >              port->ctrl&= ~(val&  0x000a);
> >+            port->ctrl&= ~(port->ctrl&  0x0040); /* clear port resume 
> >detected */
> >          }
> 
> This chunk looks suspicious ...
> 
> I suspect the port suspend/resume emulation isn't complete.
> 
> /me goes debugging,
>   Gerd

CONFIG_USB_DEBUG helps.