I just installed a fresh KDE neon, Skanlite 2.2.0.0 and nvidia-driver-455. I use a 1600x1200 display and UI of all other applications is pretty snappy. Skanlite on the other hand, takes about 3 seconds for a simple UI actions, e.g. selecting Scan resolution, both in landscape and portrait modes. I have a relatively modern, 4 core, 3.3GHz Intel i5 CPU, 8GB RAM and GeForce GT 730 GPU. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE neon 5.20 (available in About System) KDE Plasma Version: 5.20.3 KDE Frameworks Version: 5.75.0 Qt Version: 5.15.1
Thanks for the report. Are you by any chance using a Canon network scanner with the pixma backend? I have one of those and that backend has a strange sleep, in the network communication, that freezes the UI thread :(
Yes, I'm using Canon MF232w, which gives me a lot of problems. I tried to make it work through USB, but that failed. It works through Ethernet, but the throughput is low. I don't know about pixma backend, I just installed `linux-UFRII-drv-v520-usen` driver from Canon.
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In my opinion this is a bug in the pixma backend, but I'm wondering a bit about if we should disable the polling of hardware buttons feature. The HW button polling works really bad on all the scanners I have tested with...
Hi all. I am using the Canon MF237w, and am facing the same issue. When I open Skanlite, it gives me the option of connecting via the Pixma backend or the ESCL backend. The ESCL backend works flawlessly, but the Pixma backend is slow. If you have any patch that you would like me to test, just let me know.
Hello all, Skanlite is very very sloooow through LAN connection, it freezes approx. 1 minute at each UI change (changing a parameter through the UI like opening a scrolling menu, change tab...). Sometimes, it crashes completely. Note that Skanlite works perfectly through USB. I can use Simple-Scan instead, which works perfectly with LAN connection, but I would prefer Skanlite because of its advanced functions. I don't know what information or log you need to investigate, I keep this thread open in my browser to answer quite quickly. My Hardware (even I don't think it is the cause) : Canon MG3650, connected on a Raspberry Pi, which works perfectly on all configurations (Linux & Windows), excepting Skanlite over LAN. Thanks for your help ! ;)
A possibly relevant merge request was started @ https://invent.kde.org/graphics/libksane/-/merge_requests/53
(In reply to Bug Janitor Service from comment #7) > A possibly relevant merge request was started @ > https://invent.kde.org/graphics/libksane/-/merge_requests/53 I disagree, pixma network backend works perfectly with simple-scan !
Note: We are _not_ disabling the backend, just the one feature of polling of the read-only options (like detecting a button being pressed on the scanner). Since Simple-scan does not seem to support that feature, it does not get bitten by it's problems either. Once this feature is disabled the scanning should be fine again. So basically we disable just that one feature that does not work. The new (sad) thing here is that this is the first time that we check what backend is in use, in stead of being generic.
(In reply to Kåre Särs from comment #9) > Note: We are _not_ disabling the backend, just the one feature of polling of > the read-only options (like detecting a button being pressed on the > scanner). Since Simple-scan does not seem to support that feature, it does > not get bitten by it's problems either. Once this feature is disabled the > scanning should be fine again. > > So basically we disable just that one feature that does not work. The new > (sad) thing here is that this is the first time that we check what backend > is in use, in stead of being generic. OK, I apologize, I didn't understand that way. I hope it will solve the problem ! ;) Thank you !
Git commit 04cf0249370b42ac7f9146a67b6545e68cb2e723 by Kåre Särs. Committed on 18/10/2021 at 14:29. Pushed by sars into branch 'master'. Naughty-list pixma network backend option polling The Pixma network backend behaves badly. polling a value will result in 1 second sleeps for every poll. The problem has been reported, but no easy/quick fix was available and the bug has been there for multiple years. Since this destroys the usability of the backend totally, we simply put the backend on the naughty list and disable the option polling. M +20 -9 src/ksanecore_p.cpp M +1 -0 src/ksanecore_p.h https://invent.kde.org/graphics/libksane/commit/04cf0249370b42ac7f9146a67b6545e68cb2e723
Git commit 2bdbe999808a225f1cfa10f10a4fcf09e45444e4 by Kåre Särs. Committed on 18/10/2021 at 15:17. Pushed by sars into branch 'release/21.08'. Naughty-list pixma network backend option polling The Pixma network backend behaves badly. polling a value will result in 1 second sleeps for every poll. The problem has been reported, but no easy/quick fix was available and the bug has been there for multiple years. Since this destroys the usability of the backend totally, we simply put the backend on the naughty list and disable the option polling. M +20 -9 src/ksanecore_p.cpp M +1 -0 src/ksanecore_p.h https://invent.kde.org/graphics/libksane/commit/2bdbe999808a225f1cfa10f10a4fcf09e45444e4