Steam input polling rate locked at 125 hz on Linux instead of the 500hz utilized in Windows

[garret-more-stories]

Your system information

• Steam client version 1759461205:
• Distribution: CachyOS
• Opted into Steam client beta?: Yes (Issue happens in both stable and beta)
• Have you checked for system updates?: Yes
• Steam Logs: N/A
• GPU: AMD (Steam Deck)

Please describe your issue in as much detail as possible:

On windows Steam Input runs at a maximum of 500hz and upscales gyro inputs to 500hz when using Gyro to Mouse [Beta]. This ensures smooth gyro motion alongside respectable input lag for controllers that poll at high rates. This seems to occur with any controller that is being used.

Unfortunately on Linux, controller poll rates are capped to 125hz. This is strange given how it works differently when using steam input on windows and how controllers on Linux can natively poll way beyond 125hz when not using steam input without issue.

Steps for reproducing this issue:

1. Install Evtest on your linux distro of choice
2. Run your terminal as a non steam game and run Evtest
3. Select Microsoft xbox pad [arbitrary number] (This is the emulated xbox controller that steam input sends)
4. Rotate the stick slowly
5. Measure the time differences between inputs. You'll notice an average time gap of 0.008s (indicating a polling rate of 125hz)
6. Run Evtest by itself without steam input and do the same test, this time selecting the name of your controller
7. Measure the time differences between inputs again. You'll notice that the average time gap will correspond to your controller's poll rate (for example 0.004s for a 250hz device)

Hopefully this issue will be solved to create parity between the OS's. It would be a shame if windows ended up being better for gaming due to a limitation in steam input polling rate.