Re: [PATCH] HID: hid-input: avoid splitting keyboard, system and consumer controls
From: Benjamin Tissoires <hidden>
Date: 2021-01-14 09:25:01
Also in:
lkml
Hi Dmitry, On Thu, Jan 14, 2021 at 7:24 AM Dmitry Torokhov [off-list ref] wrote:
quoted hunk ↗ jump to hunk
A typical USB keyboard usually splits its keys into several reports: - one for the basic alphanumeric keys, modifier keys, F<n> keys, six pack keys and keypad. This report's application is normally listed as GenericDesktop.Keyboard - a GenericDesktop.SystemControl report for the system control keys, such as power and sleep - Consumer.ConsumerControl report for multimedia (forward, rewind, play/pause, mute, etc) and other extended keys. - additional output, vendor specific, and feature reports Splitting each report into a separate input device is wasteful and even hurts userspace as it makes it harder to determine the true capabilities (set of available keys) of a keyboard, so let's adjust application matching to merge system control and consumer control reports with keyboard report, if one has already been processed. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- drivers/hid/hid-input.c | 10 ++++++++++ 1 file changed, 10 insertions(+)diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index f797659cb9d9..df45d8d07dc2 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c@@ -1851,6 +1851,16 @@ static struct hid_input *hidinput_match_application(struct hid_report *report) list_for_each_entry(hidinput, &hid->inputs, list) { if (hidinput->application == report->application) return hidinput; + + /* + * Keep SystemControl and ConsumerControl applications together + * with the main keyboard, if present. + */ + if ((report->application == HID_GD_SYSTEM_CONTROL || + report->application == HID_CP_CONSUMER_CONTROL) && + hidinput->application == HID_GD_KEYBOARD) {
I am not fundamentally against the patch, but I think that if the device exposes first a HID_CP_CONSUMER_CONTROL and then a HID_GD_KEYBOARD we will end up with 2 different input nodes. We likely need to "convert" HID_GD_SYSTEM_CONTROL and HID_CP_CONSUMER_CONTROL to HID_GD_KEYBOARD when creating the hidinput. Cheers, Benjamin
+ return hidinput;
+ }
}
return NULL;
--
2.30.0.284.gd98b1dd5eaa7-goog
--
Dmitry