On Mon, 2011-08-29 at 15:02 -0700, Sarah Sharp wrote:
> On Wed, Aug 17, 2011 at 06:01:36PM +0800, Andiry Xu wrote:
> > Check device's LPM capability by examining the bmAttibutes field of the
> > USB2.0 Extension Descriptor.
> >
> > Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
> > ---
> > drivers/usb/core/hub.c | 10 ++++++++--
> > include/linux/usb.h | 2 ++
> > 2 files changed, 10 insertions(+), 2 deletions(-)
> >
> <snip>
>
> > diff --git a/include/linux/usb.h b/include/linux/usb.h
> > index cfd571b..cf13924 100644
> > --- a/include/linux/usb.h
> > +++ b/include/linux/usb.h
> > @@ -410,6 +410,7 @@ struct usb_tt;
> > * FIXME -- complete doc
> > * @authenticated: Crypto authentication passed
> > * @wusb: device is Wireless USB
> > + * @lpm_capable: device supports LPM
> > * @string_langid: language ID for strings
> > * @product: iProduct string, if present (static)
> > * @manufacturer: iManufacturer string, if present (static)
> > @@ -472,6 +473,7 @@ struct usb_device {
> > unsigned authorized:1;
> > unsigned authenticated:1;
> > unsigned wusb:1;
> > + unsigned lpm_capable:1;
>
> Are you planning on reusing this variable for USB 3.0 LPM, or will it be
> used for USB 2.0 LPM only? If it's only for USB 2.0 LPM, the variable
> name should probably be usb2_lpm_capable and the comment should change
> as well.
>
> I could see this being used for testing USB 3.0 LPM as well. We might
> need to run a test in the xHCI driver to catch those USB 3.0 devices
> that don't implement USB 3.0 LPM. But we'd need to be able to check the
> device speed in the xHCI driver if we were going to reuse this variable,
> so that we don't run the USB 2.0 LPM test on a USB 3.0 device. What do
> you think?
>
This variable should be used for both USB2 and USB3 LPM, because USB3
spec does not redefine any different descriptor for LPM capability.
Current usb2 software LPM test code checks hcd speed at the beginning to
make sure it doesn't run USB2 LPM for USB3 devices. However there is a
bug - I used xhci_to_hcd() to get the hcd and check its speed. It's
wrong since the function will always return main_hcd. I'll modify the
code to pass the hcd variable to xhci_usb2_software_lpm_test() directly
to fix the bug.
Thanks,
Andiry
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