HID: usbhid: skip interrupt IN polling for devices with no input reports - #7
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usbhid starts polling a device's interrupt IN endpoint on open (usbhid_open() -> hid_start_in()). If the report descriptor declares no input reports there is nothing to read there, so the poll is useless, and on some composite devices it is also harmful. The ASUS ROG N-Key keyboards expose a second, input-less interface used only for RGB control via feature reports. Opening its hidraw node (any hidraw reader does, including SDL/Steam Input or a plain cat) starts the pointless IN poll and keypress reports on the keyboard interface get dropped for as long as the node stays open: a lost key-down drops a letter, a lost key-up leaves the key stuck. usbmon shows the dropped reports never reach the URB layer. The useless poll itself is long-standing; commit 4ac74ea ("HID: asus: early return for ROG devices") is what exposes it on these devices by keeping the input-less interface alive instead of ejecting it, so its hidraw node can be opened and the poll started. Skip the poll in usbhid_open() when the device has no input reports. Feature reports and hidraw output keep working over the control and OUT endpoints, so the interface is otherwise unaffected. Fixes: 4ac74ea ("HID: asus: early return for ROG devices") Link: https://discuss.cachyos.org/t/keyboard-input-issues-on-asus-rog-strix-16-2025-with-cachyos-during-gaming/30823 Link: ublue-os/bazzite#4590 Cc: stable@vger.kernel.org Tested-by: Kerim Kabirov <the.privat33r+linux@pm.me> Tested-by: GameBurrow <gameburrow@pm.me> Signed-off-by: Ahmed Yaseen <yaseen@ghoul.dev> Reviewed-by: Denis Benato <denis.benato@linux.dev>
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From LKML. Already in OGC 7.1.3
https://lore.kernel.org/all/20260828104159.62399-2-yaseen@ghoul.dev/