Linux 5.9 HID Has Improvement For Faster Probe/Boot Time
The HID changes for Linux 5.9 aren't too many but there are a few worth mentioning for improving input device support on Linux.
Among the HID items worth calling out for Linux 5.9 include:
- The USB HID code will no longer sleep when opening a device. This was done to allow queues to drain when starting out but can result in slowing down the device probing and decreasing the boot speed. Instead with Linux 5.9 it will simply start processing of input events later on but not slow down the probing in order to expedite the boot time.
- The HID input code has worked around some devices like the 3DConnexion Spacemouse Wireless 3D controller that return more than just two bytes for the battery report. Up to now for those devices having a larger than expected size for the battery report due to appending device-specific fields, the input hardware can enter a loop of being reset every two seconds as a result. Linux 5.9 now allows up to four bytes rather than two for the battery report to workaround this problem.
- Support for the ThinkPad 10 Ultrabook keyboard.
The list of HID changes for this new kernel cycle via this pull request.