On Mon, 29 Nov 2010, Sarah Sharp wrote: > Make the USB 3.0 roothub registered by the USB core have a SuperSpeed > Endpoint Companion Descriptor after the interrupt endpoint. All USB 3.0 > devices are required to have this, and the USB 3.0 bus specification > (section 10.13.1) says which values the descriptor should have. > > Unfortunately, it doesn't specify what the wBytesPerInterval should be, so > I copied a value from a USB 3.0 hub prototype. > + /* one SuperSpeed endpoint companion descriptor */ > + 0x06, /* __u8 ss_bLength */ > + 0x30, /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */ > + 0x00, /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */ > + 0x00, /* __u8 ss_bmAttributes; 1 packet per service interval */ > + 0x02, 0x00 /* __le16 ss_wBytesPerInterval; XXX: is this correct?? */ > }; 2 is undoubtedly the correct value, since the spec says that SuperSpeed hubs can't have more than 15 downstream ports. 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
