[PATCH v2 0/1] HID: usbhid: skip interrupt IN polling for devices with no input reports

[Ahmed Yaseen <yaseen@ghoul.dev>]

On some ASUS ROG N-Key keyboards, a second input-less interface is
exposed for RGB control. Polling this interface causes keypress reports
on the first keyboard interface to be dropped: a lost key-down drops a
letter, a lost key-up leaves the key stuck. Any hidraw reader opening
the node is enough to trigger it, including SDL/Steam Input or a plain
cat.

This patch skips the poll if no input reports exist for an interface. A
device with no input reports has no benefit from being polled, so
instead of adding a new quirk, I have opted to skip it entirely.

Devices other than the ASUS ones are unaffected. HID core already
discards whatever arrives on the interrupt IN endpoint of an interface
that declares no input reports: hid_get_report() matches nothing, so
neither ->raw_event() nor hidraw and hiddev are ever reached.

The affected machines are 2024-2025 Strix SCAR 16/18 (G635L/G835L) and
G16/G18 (G615L/G815L) laptops, and the bug is widely reported across
distributions, so I would appreciate this being considered for the
current cycle. Reports:

https://discuss.cachyos.org/t/keyboard-input-issues-on-asus-rog-strix-16-2025-with-cachyos-during-gaming/30823
https://github.com/ublue-os/bazzite/issues/4590

v1: https://lore.kernel.org/all/20260605113952.38435-1-yaseen@ghoul.dev

Changes since v1:
- Added a short comment above the condition in usbhid_open() explaining
  the reason for skipping there.
- Added Cc: stable@vger.kernel.org; v1 was not marked for backport. The
  bug reaches every tree carrying 4ac74ea68f64, i.e. v7.0 onwards.
- Added Link: tags for two of the downstream bug reports.
- No functional change: the hunk is byte-identical to v1 apart from the
  new comment, so the Tested-by and Reviewed-by tags carry over.

Since v1, this patch has been adopted by three downstream kernels, with
no regressions reported by any user since:
- OGC kernel: from v7.1.3-ogc5 (2026-07-21) onwards
- Nobara kernel: from 7.1.4 onwards
- G14 kernel: from 7.1.4 onwards

Ahmed Yaseen (1):
  HID: usbhid: skip interrupt IN polling for devices with no input
    reports

 drivers/hid/usbhid/hid-core.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)


base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f
-- 
2.55.0