On Wed, 02 Mar 2022 12:45:17 -0600 Cameron <cameronghall@xxxxxxx> wrote: > Hello all, > > This is my first time reporting a kernel issue, so please let me know > if this is not the right place to report it. I am using a third party > PowerA USB wired Switch controller on Void Linux. Games and > applications are able to successfully detect and use the controller, > however the button mapping is very wrong in every program I have > tested. I tested this with evtest-qt to see what button values evdev > is reporting. Since there appears to be no way to remap these from > userspace, I suspect the problem lies in the kernel driver. > > Pressing the two analog sticks (which should be BTN_THUMBL and > BTN_THUMBR) incorrectly generate events for BTN_SELECT and BTN_START, > and pressing the + and - buttons (which should be mapped to BTN_START > and BTN_SELECT) instead result in BTN_TL2 and BTN_TR2 events. > > The device in question (as reported by lsusb) is: > Bus 001 Device 003: ID 20d6:a711 Core (Plus) Wired Controller > and I am using kernel version 5.15.26_1 on Void Linux. > > I understand that this gamepad is intended to be used with the > Nintendo Switch console, so it may not be as HID compliant as, say, a > Logitech. However the kernel has a standard for how these buttons are > to be mapped, which the driver used for this gamepad appears to > violate. https://www.kernel.org/doc/html/v4.13/input/gamepad.html > Section 4.3 states: "All new gamepads are supposed to comply with > this mapping. Please report any bugs, if they don’t." > > I can provide more info if needed. > > Thanks, > Cameron So, here's an update on this situation. I managed to hack around this situation by writing a simple kernel module to override the button mapping for this device. The code for the module can be found on my GitHub here: https://gist.github.com/camthesaxman/af7099505103a555518741b4083eaea8 I have almost zero experience with kernel development, so I don't know how this kind of thing would be properly fixed in-tree (perhaps something with hid-quirks.c?) and make a proper patch for the kernel. Thanks, Cameron
