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

[Denis Benato]

13 ott 2026 15:55:33 Thorsten Leemhuis <regressions@xxxxxxxxxxxxx>:

> On 8/28/26 12:42, Ahmed Yaseen wrote:
>> 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.
>
> Hmmm, what's the status here? Ahmed, is this still needed, or was this
> fixed in some other way? From the the outside it looks a lot like this
> regression fix feel through the cracks, but would be good to get into
> 7.4-rc1 to finally fix the dropped keypress reports.
>

Hi Thorsten,

This is very much needed and we had to include it in OGC kernel to avoid hid devices resetting constantly.

It is a very important fix and we are waiting for inclusion upstream because games becomes flat out unplayable with certain combination of tools.

Best regards,
Denis Benato

> Ciao, Thorsten
>> 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@xxxxxxxxxxxxxxx
>> Tested-by: Kerim Kabirov <the.privat33r+linux@xxxxx>
>> Tested-by: GameBurrow <gameburrow@xxxxx>
>> Signed-off-by: Ahmed Yaseen <yaseen@xxxxxxxxx>
>> Reviewed-by: Denis Benato <denis.benato@xxxxxxxxx>
>> ---
>> drivers/hid/usbhid/hid-core.c | 9 ++++++++-
>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> 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;
>>     }
>>
>> base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f