<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><div><div>On May 2, 2026, at 12:25 PM, Gavin Davenport <gavdav@gavdav.net> wrote:</div><br class="Apple-interchange-newline"></div><blockquote type="cite"><meta charset="UTF-8"><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0cm; font-size: 11pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">It appears to be periodically making a new device file - shortly after boot dmesg emits:</span></div></div></blockquote><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0cm; font-size: 11pt; font-family: Calibri, sans-serif;"><br></div><div style="margin: 0cm; font-size: 11pt; font-family: Calibri, sans-serif;">That's not ideal. ushbid-ups tries to reconnect, but if you have a physical layer USB issue that results in frequent disconnections, I'd want to resolve that first, because the reconnection takes time and can't possibly cover all corner cases.</div><div style="margin: 0cm; font-size: 11pt; font-family: Calibri, sans-serif;"><br></div></div><blockquote type="cite"><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0cm; font-size: 11pt; font-family: Calibri, sans-serif;"></div><div style="margin: 0cm; font-size: 11pt; font-family: Calibri, sans-serif;"><span>I don't understand why udev is no help here. Is there any reference information i can look at to understand why (I can’t use udev rules to help) ?<o:p></o:p></span></div></div></blockquote><br></div><div>As background, most of the USB drivers in NUT use libusb, mostly libusb-1.0 but nut-2.8.4 still has libusb-0.1 compatibility code, and can switch between them at build time. Regardless of the version, libusb targets more than just Linux.</div><div><br></div><div>It's similar to this thread: <a href="https://sourceforge.net/p/libusb/mailman/libusb-devel/thread/4E0DE417.1030004@gmail.com/">https://sourceforge.net/p/libusb/mailman/libusb-devel/thread/4E0DE417.1030004@gmail.com/</a></div><div><br></div><div>At the time when I was more actively working on the usbhid-ups code, we used the most straightforward API for opening USB devices (iterating over devices, matching VID/PID and potentially other information), and that didn't include topology information beyond the bus number. </div><div><br></div><div>It looks like there is also "busport" in 2.8.4, which might help (though it also does not use /dev node names): <a href="https://networkupstools.org/docs/man/usbhid-ups.html#:~:text=busport%20=%20regex,-OPTIONAL%2C%20NOT%20RECOMMENDED">https://networkupstools.org/docs/man/usbhid-ups.html#:~:text=busport%20=%20regex,-OPTIONAL%2C%20NOT%20RECOMMENDED</a></div><div><br></div><div>Maybe someone else (Jim?) can comment on the "Optional, not recommended" note.</div></body></html>