Hi, Alan, > > > You have to explain more clearly how the Xilinx controller expects to > > > receive these messages. > > > > > > > I am not sure whether it is possible. But a control message of > > HUB_CLEAR_TT_BUFFER is expected to clear the tt buffers inside TT for a > > particular endpoint, just like the one in hub_clear_tt_buffer(). My > > understanding is that this message will be addressed to the root hub, > > however, it will go through the TT, and get executed there. > > Your understanding must be wrong or confused. For instance, what > device address do you think this message will be sent to? Don't say > address 0 -- that address is reserved for use by new devices before > they have been enumerated. > > Can you check up on this and find out the correct answer? > > Alan Stern > I checked and found that in Xilinx's Host controller case, the time that the TT is enabled is because a FS device is directly connected. The TT therefore knows the HS control transfer, HUB_CLEAR_TT_BUFFER, must be for the TT itself. All traffic to downstream would be split transfers, since the host controller is directly connected to a FS device. So, the device address for the HS control transfer of HUB_CLEAR_TT_BUFFER is not critical for the control message to reach the TT. The port address is useful to find which port's TT. However, Xilinx's EHCI host controller only has one port. I do think this is not a pretty solution. I think we will hold this and wait for a solution in Linux, and will adjust our hardware to that (we are taking the advantage of FPGA). Thanks, Julie. This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. -- 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
