On Fri, 10 Jul 2020, Darren Hart wrote: > > Some devices, particularly the 3DConnexion Spacemouse wireless 3D > > controllers, return more than just the battery capacity in the battery > > report. The Spacemouse devices return an additional byte with a device > > specific field. However, hidinput_query_battery_capacity() only > > requests a 2 byte transfer. > > > > When a spacemouse is connected via USB (direct wire, no wireless dongle) > > and it returns a 3 byte report instead of the assumed 2 byte battery > > report the larger transfer confuses and frightens the USB subsystem > > which chooses to ignore the transfer. Then after 2 seconds assume the > > device has stopped responding and reset it. This can be reproduced > > easily by using a wired connection with a wireless spacemouse. The > > Spacemouse will enter a loop of resetting every 2 seconds which can be > > observed in dmesg. > > > > This patch solves the problem by increasing the transfer request to 4 > > bytes instead of 2. The fix isn't particularly elegant, but it is simple > > and safe to backport to stable kernels. A further patch will follow to > > more elegantly handle battery reports that contain additional data. > > > > Applied and tested on 5.8.0-rc4+ (aa0c9086b40c) with a 3Dconnexion > SpaceMouse Wireless (tested connected via USB). Observed the same > behavior Grant reports before the patch. After the patch, the device stays > connected successfully. > > Tested-by: Darren Hart <dvhart@xxxxxxxxxxxxx> Applied, thanks. -- Jiri Kosina SUSE Labs
