On Thursday, April 21, 2011 03:45:44 pm Alan Stern wrote: > On Wed, 20 Apr 2011, Marcel wrote: > > On Sunday, April 17, 2011 01:46:26 am Alan Stern wrote: > > > On Sat, 16 Apr 2011, Marcel wrote: > > > > Hi, > > > > > > > > > > Most likely the root cause is a hardware bug in the Atmel G45. > > > > > > However the only way to prove this would be to replace the G45 > > > > > > with a different kind of system. > > > > Just to post a reply I got from Atmel. It seem my issue is related to a > > known issue (which btw was not public yet). > > > > Errata: > > UHPHS: Packet Loss Issue in the UTMI Transceivers > > > > High-Speed USB Host may lose incoming packets when connected to an > > external USB Hub. > > > > A high data transfer error rate has been observed on the High-Speed USB > > Host interface when connected to an external USB Hub. The USB remains > > functional but the errors may require a reset of the USB interface to > > recover. > > > > The Full-Speed USB Host operation is not affected by this problem. > > > > Problem Fix/Workaround > > > > A workaround consists of implementing a timeout on the USB communication > > using one of the timers in the device and trigger a reset of the USB > > Host interface via software and restart the communication. The impact of > > the workaround on the data rate is depending on the error rate observed > > in the application but can be such that streaming data at high rates > > becomes impractical. > > Too bad. This may not be exactly the error that you see, but it seems > pretty close. > > > They mention packet loss. This may be true as the error I got (bad packet > > length) always occurred at a moment where I should have received incoming > > data. I than received a packet, no further packets. > > > > In short, I have no other workaround than to use full speed hubs. > > I think for now we can close this subject and I think Alan's first > > impression as mentioned above was after all true (unfortunately). > > Can you use non-Atmel hardware instead? I have an option to do that, but it will take some time before I can do that because I will be away for business for some time. It will certainly take a couple of months before I can try it. Best regards, Marcel -- 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
