On Thu, 4 Mar 2010, Andiry Xu wrote: > Thanks for the comments. I don't know how external USB3.0 hub behaves > since I don't have one, but the xHC root hub contains both USB2 and USB3 > protocol ports. The behavior of external hubs is defined in the USB-3.0 spec. They register as two separate devices, once on the SuperSpeed bus and once on the high-speed bus. > I only need to apply to the USB3 ports in the root hub. > In this case should I give a test for the hub rather than the port? > > I didn't notice (1 << USB_PORT_FEAT_SUPERSPEED) is equal to > USB_PORT_STAT_TEST, thanks for the remind. But I just need a flag here. Making up your own flag often is not a good idea. You could do it, but that just makes things more difficult for the hub driver -- it will have to treat USB-3.0 root hubs differently from USB-3.0 external hubs. > Can we just use a workaround here? re-define USB_PORT_FEAT_SUPERSPEED to > make no conflict and I'll refine the patch with FIXME and proper comment > in code. When there is better solution we can remove it. We need this > workaround because without the patch, if xHCI bus suspend/resume is > implemented, even if you do nothing in them, the USB3.0 device will fail > to be recognized. That sounds like a critical issue. If you insist on a temporary workaround, then you'll have to do something like this. Define USB_PORT_STAT_SUPERSPEED somehow (don't call it a feature -- it's a status, not a feature) and add: If this is a USB-3.0 hub then: If it's not a root hub or if USB_PORT_STAT_SUPERSPEED is set then skip the disable Fair warning: I intend to submit a patch in the near future which will remove USB_PORT_FEAT_HIGHSPEED and USB_PORT_FEAT_SUPERSPEED. There really shouldn't be a USB_PORT_FEAT_LOWSPEED either, but that one _is_ defined in the spec (although it's not mentioned anywhere except to say that host software shall never use it). Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
