fl2k on rpi4: no more USB error

Dear all, I found that the fix for the USB issue on ARM systems has finally made it into the Linux kernel, 5.6.14 and 5.7-rc6. Today I installed the latest Manjaro 64 unstable mainline kernel on my rpi4 and made some quick tests with fl-wspr (https://github.com/tejeez/fl2k-tool). There are no more USB errors*, but I still get underflow errors at high sample rates. In my quick tests the maximum reliable sample rate was about 20 MHz when running in an X session with other programs. When I stopped the X server and ran in a text console I could go above 30 MHz without underflows. This means that the rpi4 is fine as an SDR transceiver for many purposes- but it would be nice to know if it is possible to tune the system for a bit higher sample rates! All the best SM2YHP Fredrik * Installed AUR package libosmo-fl2k-git to fix other USB device issues -- ------------------ Carl-Fredrik Enell Föraregatan 26B SE-98139 Kiruna +46705508256 -----------------