Re: [PATCH v10 05/11] HID: asus: move vendor initialization to probe

Ilpo Järvinen
2025-12-08T17:11:29Z

On Sat, 22 Nov 2025, Antheas Kapenekakis wrote:

> ROG NKEY devices have multiple HID endpoints, around 3-4. One of those
> endpoints has a usage page of 0xff31, and is the one that emits keyboard
> shortcuts and controls RGB/backlight. Currently, this driver places
> the usage page check under asus_input_mapping and then inits backlight
> in asus_input_configured which is unnecessarily complicated and prevents
> probe from performing customizations on the vendor endpoint.
>
> Simplify the logic by introducing an is_vendor variable into probe that
> checks for usage page 0xff31. Then, use this variable to move backlight
> initialization into probe instead of asus_input_configured, and remove
> the backlight check from asus_input_mapping.

In the changelogs, please add () after any name that refers to a C
function so the reader immediately knows you're talking about a function.

> Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
> ---
> drivers/hid/hid-asus.c | 35 ++++++++++++++++++-----------------
> 1 file changed, 18 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 2a412e10f916..faac971794c0 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -48,6 +48,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
> #define T100CHI_MOUSE_REPORT_ID 0x06
> #define FEATURE_REPORT_ID 0x0d
> #define INPUT_REPORT_ID 0x5d
> +#define HID_USAGE_PAGE_VENDOR 0xff310000
> #define FEATURE_KBD_REPORT_ID 0x5a
> #define FEATURE_KBD_REPORT_SIZE 64
> #define FEATURE_KBD_LED_REPORT_ID1 0x5d
> @@ -127,7 +128,6 @@ struct asus_drvdata {
> struct input_dev *tp_kbd_input;
> struct asus_kbd_leds *kbd_backlight;
> const struct asus_touchpad_info *tp;
> - bool enable_backlight;
> struct power_supply *battery;
> struct power_supply_desc battery_desc;
> int battery_capacity;
> @@ -318,7 +318,7 @@ static int asus_e1239t_event(struct asus_drvdata *drvdat, u8 *data, int size)
> static int asus_event(struct hid_device *hdev, struct hid_field *field,
> struct hid_usage *usage, __s32 value)
> {
> - if ((usage->hid & HID_USAGE_PAGE) == 0xff310000 &&
> + if ((usage->hid & HID_USAGE_PAGE) == HID_USAGE_PAGE_VENDOR &&
> (usage->hid & HID_USAGE) != 0x00 &&
> (usage->hid & HID_USAGE) != 0xff && !usage->type) {
> hid_warn(hdev, "Unmapped Asus vendor usagepage code 0x%02x\n",
> @@ -941,11 +941,6 @@ static int asus_input_configured(struct hid_device *hdev, struct hid_input *hi)
>
> drvdata->input = input;
>
> - if (drvdata->enable_backlight &&
> - !asus_kbd_wmi_led_control_present(hdev) &&
> - asus_kbd_register_leds(hdev))
> - hid_warn(hdev, "Failed to initialize backlight.\n");
> -
> return 0;
> }
>
> @@ -1018,15 +1013,6 @@ static int asus_input_mapping(struct hid_device *hdev,
> return -1;
> }
>
> - /*
> - * Check and enable backlight only on devices with UsagePage ==
> - * 0xff31 to avoid initializing the keyboard firmware multiple
> - * times on devices with multiple HID descriptors but same
> - * PID/VID.
> - */
> - if (drvdata->quirks & QUIRK_USE_KBD_BACKLIGHT)
> - drvdata->enable_backlight = true;
> -
> set_bit(EV_REP, hi->input->evbit);
> return 1;
> }
> @@ -1143,8 +1129,11 @@ static int __maybe_unused asus_reset_resume(struct hid_device *hdev)
>
> static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
> {
> - int ret;
> + struct hid_report_enum *rep_enum;
> struct asus_drvdata *drvdata;
> + struct hid_report *rep;
> + bool is_vendor = false;
> + int ret;
>
> drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
> if (drvdata == NULL) {
> @@ -1228,12 +1217,24 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
> return ret;
> }
>
> + /* Check for vendor for RGB init and handle generic devices properly. */
> + rep_enum = &hdev->report_enum[HID_INPUT_REPORT];
> + list_for_each_entry(rep, &rep_enum->report_list, list) {
> + if ((rep->application & HID_USAGE_PAGE) == HID_USAGE_PAGE_VENDOR)
> + is_vendor = true;
> + }
> +
> ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> if (ret) {
> hid_err(hdev, "Asus hw start failed: %d\n", ret);
> return ret;
> }
>
> + if (is_vendor && (drvdata->quirks & QUIRK_USE_KBD_BACKLIGHT) &&
> + !asus_kbd_wmi_led_control_present(hdev) &&
> + asus_kbd_register_leds(hdev))
> + hid_warn(hdev, "Failed to initialize backlight.\n");
> +
> /*
> * Check that input registration succeeded. Checking that
> * HID_CLAIMED_INPUT is set prevents a UAF when all input devices
>

--
i.