From 46381fa56ad5311df8f329538b0cf75077cf5d23 Mon Sep 17 00:00:00 2001 From: Ahmed Yaseen Date: Wed, 3 Jun 2026 22:09:45 +0500 Subject: [PATCH] [FROM-ML] 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") Tested-by: Kerim Kabirov Tested-by: GameBurrow Signed-off-by: Ahmed Yaseen --- drivers/hid/usbhid/hid-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index 5af93b9b1fb56..8bbcec63fc766 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -687,7 +687,8 @@ static int usbhid_open(struct hid_device *hid) set_bit(HID_OPENED, &usbhid->iofl); - if (hid->quirks & HID_QUIRK_ALWAYS_POLL) { + if ((hid->quirks & HID_QUIRK_ALWAYS_POLL) || + list_empty(&hid->report_enum[HID_INPUT_REPORT].report_list)) { res = 0; goto Done; }