Thanks, Alan, At least we know that it is not a hardware bug. Thanks, Julie. > -----Original Message----- > From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- > owner@xxxxxxxxxxxxxxx] On Behalf Of Alan Stern > Sent: Friday, September 11, 2009 2:31 PM > To: Julie Zhu > Cc: linux-usb@xxxxxxxxxxxxxxx > Subject: Re: sitd OUT s-mask cross frame boundary > > On Fri, 11 Sep 2009, Julie Zhu wrote: > > > Hi, all, > > > > We are testing the USB Host controller from Xilinx using a PowerPC > > platform. This test is FS isochronous OUT, with the maxp 1023 and > > interval 1ms. We noticed that with direct connection between the host > > controller and the FS iso OUT device, the s-mask is 0x3f. And the test > > finished fine. > > > > However, if the device is connected through a FS hub, then the sitd > > s-mask becomes 0x1f8, this makes the 6th packet crosses the frame > > boundary. From EHCI spec page 104, section 4.12.3.1, it says under Case > > 2a: > > > > Software must never schedule full-speed isochronous OUTs across > > an H-Frame boundary. > > > > The test therefore failed, because the host controller never put the 6th > > packet out. > > > > The kernel version is 2.6.30. > > > > The function sitd_slot_ok() shifts the s-mask by the starting frame > > number. It does check for crossing frame boundary for IN case, but never > > does anything for OUT. I wonder whether it is a bug? Or, it is intended? > > It is a bug. The code in ehci-sched.c for dealing with split > transactions needs a lot of work. For example, it doesn't support > FSTNs. In the case you noticed, the code checks for CSPLITs crossing a > frame boundary but not for SSPLITs. > > 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 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
