On Tue, Nov 30, 2010 at 10:58:09AM -0500, Alan Stern wrote: > 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. Ok, right, I see the note in section 10.11.4 now. Sarah Sharp -- 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
