Jeremy L Rosenberger wrote: > This may not be a particularly useful e-mail since it will be a little > short on specifics, but hopefully it may provide enough information to > give someone (with more knowledge of SANE internals than I have) an idea > of what might be going on. > > Once upon a time, I used my Microtek X6 USB with Windows 2000 and with > SANE on Linux. The performance under both was about equal. This was on a > 750MHz Athlon system with a VIA chipset using some variant of the 2.4 > kernel. > > Then, somewhere along the line of 2.4 kernel versions (using the uhci, > or "alternate" UHCI driver) and SANE versions, things stopped working: > The scanner lamp would turn on and move about an inch before "hanging." > I can't recall whether this locked up the machine or not. Unfortunately > I don't know whether this problem was ever resolved, because I stopped > using said Athlon system and now pretty much exclusively use my laptop, > which is a 700MHz Pentium III. > > Now on my laptop (still using the "alternate" uhci kernel driver), > scanning works but is much slower than it was before. (Of course this > could be due to the new hardware, but there is near parity in the two > machines' capabilities.) I tried a couple of color scans at 200dpi and > 300dpi, and the scanner head will move about an inch, pause for a few > seconds, move another inch, pause, and so on. (Before, the motion was > pretty much continuous.) It's as if the scanner is producing data too > quickly and has to wait for the computer to catch up (although this > doesn't seem very likely). > > I'd be happy to do additional testing and provide more data, if someone > would tell me what sort of data (perhaps turn on debugging somewhere and > send log output?) would be interesting. > > Of course, I am glad that even though it's slow, it works! :-)
I've seen the same with the uhci USB driver, getting a throughput of something like only 60 kB/s. I think it happened somewhere between kernel version 2.4.8 and 2.4.16. I'm now running 2.4.18 but I have not checked whether it has been fixed. Bertrik
