On Thu, 28 May 2015, Marc MERLIN wrote: > On Tue, May 19, 2015 at 10:56:39AM -0700, Marc MERLIN wrote: > > On Tue, May 19, 2015 at 01:21:30PM -0400, Alan Stern wrote: > > > This strongly suggests that the problem lies in the hubs (or in one of > > > them). Something caused a hub to disconnect, and when that happened > > > all of the serial ports downstream from that hub went along for the > > > ride. > > > > Hi Alan, thanks for your answer. > > > > So, when my serial ports go bad, I detect it on a high level, and one of > > my 4 port serial USB hub was connected into a powered USB hub where I > > can toggle ports on and off. > > In that case, the port got cycled, causing a full reset and things to > > start working again. > > > > But, you made me realize that my 4 and 8 port USB serial hubs are USB > > hubs themselves with 4 or 8 FTDI converts in them. > > So, I plugged the 4 port one directly into the PC (the other one was > > already directly connected too), and added external power to it just in > > case. > > > > We'll see if that helps. > > Well, looks like you were right, thank you for helping out. > > > However, I have many many logs that show that my problems are happening > > during periods of high disk activity, mostly at night when I'm running > > rsync backups, so it still looks like there is a link between the 2. > > That was still true though, and I'm not sure how disk access was > affecting USB reliability, but it was. Maybe it caused a change in the available power level. > Either way, plugging the serial converter hub directly into the PC > helped for sure. > > Thanks again, You're welcome. 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
