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@the2masters the2masters commented Dec 25, 2025

fixes float endianness issues in 3.1.8.

I use a small, custom application to convert data from my electricity meter into Modbus format for my inverter and wallbox. I developed against an earlier version of libmodbus on x86, and it ran flawlessly on my ath79 router (big endian). After migrating to a Mediatek router (little endian), the program only outputted huge, meaningless values. However, it ran perfectly fine on my x86 system (little endian), which is running Fedora with libmodbus v3.1.11.

I then found upstream bug reports stephane/libmodbus#665 stephane/libmodbus#757 and the changelog of libmodbus v3.1.11 with the fix. Update openwrt to libmodbus v3.1.11 to get the fix.

📦 Package Details

Maintainer: @mhei


🧪 Run Testing Details

  • OpenWrt Version: master
  • OpenWrt Target/Subtarget: ath79, mediatek/filogic, x86/64
  • OpenWrt Device: tplink_archer-c7-v2, bananapi_bpi-r4, x86 virtual machine

✅ Formalities

  • I have reviewed the CONTRIBUTING.md file for detailed contributing guidelines.

@the2masters the2masters changed the title cccccbugjftvkedjjkenligcejftvtjnbcbgbnhcnnudlibmodbus: update to 3.1.11 libmodbus: update to 3.1.11 Dec 25, 2025
@BKPepe
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BKPepe commented Dec 26, 2025

The commit description could be improved, don't you think? :) Right now, the subject and description are identical.

How about adding some release notes instead? Also, which "float endianness issue" are you referring to? Is there a specific issue that should be referenced?

A few more questions:

  • Was this run-tested?
  • Was it compile-tested?

So many questions... :(

Relevant release notes:

fixes float endianness issues in 3.1.8.

I use a small, custom application to convert data from my
electricity meter into Modbus format for my inverter and wallbox.
I developed this program against an earlier version of libmodbus
on x86, and it ran flawlessly on my ath79 router (big endian).
After migrating to a Mediatek router (little endian), the program
only outputted huge, meaningless values. However, it ran perfectly
fine on my x86 system (little endian), which is running Fedora
with libmodbus v3.1.11.

I then found several bug reports and the changelogs for libmodbus 3.1.11
that described and resolved my problem. So update openwrt to 3.1.11.

Signed-off-by: Stefan Hellermann <[email protected]>
@the2masters
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@BKPepe: I hope I was able to answer all your questions :-)

@mhei
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mhei commented Dec 28, 2025

I'm fine with it, so let's merge it. I also compile-tested for mxs platform, and also run-tested it on Raspi. (However, both are little-endian systems, so I cannot tell much about the endianess stuff).
Thank you.

@mhei mhei merged commit 534ca8e into openwrt:master Dec 28, 2025
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3 participants