This is from our hardware team: "Our EHCI does not have such limitation on ITD and does not preserve time for async traffic either." BTW: What platform are you using? Thanks & Regards, Libin > -----Original Message----- > From: Karsten Wiese [mailto:fzuuzf@xxxxxxxxxxxxxx] > Sent: Saturday, February 21, 2009 6:55 PM > To: Greg KH > Cc: Timo Ketolainen; Linux USB; Yang, Libin > Subject: Re: Problem(s) with ehci-hcd, us122l and HP laptop > > 2009/2/20 Greg KH <greg@xxxxxxxxx>: > > On Thu, Feb 19, 2009 at 08:45:56AM +0200, Timo Ketolainen wrote: > >> Using usbmon shows that the interface connects fine most of the times, > >> but the transfers just freeze almost immediately after the isochronos > >> transfers begin. After that nothing goes in or out until the interface > >> is disconnected. > >> > >> As a sidenote, by Googling, it seems that there has been some problems > >> with HP laptops and this interface in Win world, too. To address this > >> a "AMD USB filter driver" has been released. Can't test it though, > >> since I ditched Vista as soon as I got my hands on this laptop. > > > > That fix should already be in your kernel, AMD made it a few kernel > > releases ago, so don't worry about it. > > > > I would suggest asking the alsa developers about this, if they have seen > > the problem or have any suggestions. > > Timo has run debug-tests showing corrupted iso-in data on the beginning > of the 2nd urb received. > > At that frame the last ITD of the first urb overlaps the first ITD of > the 2nd urb: > The last ITD of the first urb uses its first 6 microframes, > the first ITD of the 2nd urb uses its last 2 microframes. > > I've added Libin to CC:. > Do some AMD-ehci only handle a single ITD per endpoint and frame? > > Thanks, > Karsten -- 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
