From 4563e596bd913fb2d5b10b2ef306c754cf97ced2 Mon Sep 17 00:00:00 2001 From: Ahmed Yaseen Date: Fri, 28 Aug 2026 10:42:21 +0000 Subject: HID: usbhid: skip interrupt IN polling for devices with no input reports 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 4ac74ea68f64 ("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: 4ac74ea68f64 ("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: https://github.com/ublue-os/bazzite/issues/4590 Cc: stable@vger.kernel.org Tested-by: Kerim Kabirov Tested-by: GameBurrow Signed-off-by: Ahmed Yaseen Reviewed-by: Denis Benato Signed-off-by: Jiri Kosina --- drivers/hid/usbhid/hid-core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index 96b0181cf819..d7cf2b56e117 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -688,7 +688,14 @@ static int usbhid_open(struct hid_device *hid) set_bit(HID_OPENED, &usbhid->iofl); - if (hid->quirks & HID_QUIRK_ALWAYS_POLL) { + /* + * ALWAYS_POLL devices are already polled from usbhid_start(), and a + * device with no input reports has nothing to send on the interrupt + * IN endpoint. In some cases polling is harmful: on the ASUS ROG + * N-Key keyboards it makes the sibling interface drop keypresses. + */ + if ((hid->quirks & HID_QUIRK_ALWAYS_POLL) || + list_empty(&hid->report_enum[HID_INPUT_REPORT].report_list)) { res = 0; goto Done; } -- cgit v1.2.3