Hi, On 2021-03-05 2:14 a.m., YuGiOhJCJ wrote: > Hello, > > I confirm that the workaround on your link is working. > If I set "SANE_DEBUG_SANEI_USB" to "5" then I am able to scan. > I confirm that it works. > > However, I don't understand how a debug variable can fix the problem. > I have seen a couple of ways that enabling debug can affect the performance of a program:
1) Changes the timing of the program, i.e. to slow it down, such that a timing issue is averted. 2) I have also seen instances where the flow of the code is altered by switching on debug so that critical code is only executed when debug is activated. I suspect that 1) above is the culprit here. Most likely the backend needed to wait for the scanner to be ready and it is not. > Is there a better way to fix that please? > There surely is, but that will have to wait for Povilas to look into it and find a solution. As always with these timing issues, diagnosing it can be a difficult task since reproduction is often problematic. I have a LiDE 220 here and it works just fine for me. There may be many variables involved to conspire to make it a rare event. We could ask you to give us some diag to pinpoint the issue, but of course that would make the problem go away :( I may have time to look into this myself but it may take some time. Cheers, Ralph
