On Fri, 2015-04-10 at 14:37 -0400, Alan Stern wrote: > On Fri, 10 Apr 2015, Steve Bangert wrote: > > > > > The reason i ask is that the performance of the drive seems slow and > > > > there were intermittent hangs during transfers based on my limited use > > > > of the drive so far. Steve > > > > > > Does this happen with both the uas and usb-storage drivers or only with > > > one of them? > > > > Both of them, i have a unpacked kernel on the drive and would do a copy > > and paste into another directory of the same drive, transfer speeds of > > 50 MB/sec are good through about half way through the transfer event > > then a hang occurs from this point on transfer speeds drop to 20MB/sec > > and then slowly ramp down to less than 5MB/sec at the end of the file > > transfer. this is with both uas and usb-storage. > > If there is a hang then no more data is getting transferred. Of course > the average transfer speed will slowly decay to 0. Okay, i _should_ have said transfer speeds are a steady 50mb/sec till about the half way point or slightly after, then a hang, then a restart of file transfer but at 20mb/sec with gradual decline of transfer speed, at/near the end of file transfer, speeds were less that 5mb/sec. > > > I have some traces, there very large and the mailing list filter will > > reject them. so i will send them directly. > > The uas trace doesn't show a hang. It just shows a bunch of normal > transfers. Interesting > > The usb-storage trace might show a hang, right at the end. The > computer tried to read 13 sectors from the disk, and there was no > response. But since this was at the end of the trace, it could simply > be that you stopped the trace before the response arrived. I started the trace about 1/3 of the way through the file transfer (to reduce trace size) and i ended the trace after file transfer completed. > > Maybe the drive isn't causing this slowdown. Some other part of the > system could be responsible. Most likely xhci Thanks for you time. Steve -- 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
