Hi, all, This is to put a closure to this thread. Yes, it is a hardware bug, and it has been fixed. Thank you all for your time, special thanks to Alan and Steve for helping out. Thanks, Julie. > -----Original Message----- > From: Alan Stern [mailto:stern@xxxxxxxxxxxxxxxxxxx] > Sent: Thursday, August 27, 2009 11:26 AM > To: Julie Zhu > Cc: Steve Calfee; linux-usb@xxxxxxxxxxxxxxx > Subject: RE: issues with FS isochronous device behind HS hub > > On Thu, 27 Aug 2009, Julie Zhu wrote: > > > Hi, Alan, > > > > Hardware trace shows that only part of the submitted sitd's are in > > there > > > > when hardware going through the periodic frame list (and they all go > > > > onto the bus), > > > > > > If the hardware doesn't see all of the submitted sitd's in the > > periodic > > > list then how can it send all of them over the bus? > > > > > > > Exactly. That is what we are to find out. The software prints (almost > > useless) show that active sitd's are unlinked in sitd_complete(). > > So these sitd's were not completed by the hardware. Have you tried > printing out the values of frame and clock_frame just before > sitd_complete() is called? > > > > > however, software saw all 100 submitted sitd's being > > > > completed, and part of the completed sitd's have their active bit > > set. > > > > > > Are you sure that all the sitd's are added to the frame list quickly > > > enough? If an sitd is added to a frame after the controller has > > > already started processing that frame then the sitd won't get > > executed. > > > > > > > Again, (almost useless) software prints show that the first sitd is > > scheduled about 29 frames away, which is 29 milliseconds, should be > > fine. And the first one is always there to be sent out, and it is on the > > bus too. It is the middle ones that are missing. And the missing starts > > when HS hub interrupt happens. > > Maybe the controller doesn't handle split transactions correctly when > an interrupt occurs between the Start-Split and the Complete-Split. > > > now_uframe sometimes overpasses clock in scan_periodic without roundup > > the frame list happening. Need to verify though. > > I'm not sure what you mean by "roundup", but this should not be > possible. > > Alan Stern > 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
