Re: [PATCH v7 4/9] HID: asus: prevent binding to all HID devices on ROG

[Denis Benato <benato.denis96@gmail.com>]

On 10/18/25 12:17, Antheas Kapenekakis wrote:
> Currently, when hid-asus is not loaded, NKEY keyboards load as ~6
> event devices with a pretty ASUSTEK name. When it loads, it concatenates
> all applications per HID endpoint, renames them, and prints errors
> when some of them do not have an input device.
>
> Therefore, change probe so that this is no longer the case. Stop
> renaming the devices, omit the check for .input which causes errors on
the devices -> devices
> e.g., the Z13 for some hiddev only devices, and add
> HID_QUIRK_INPUT_PER_APP so that each application gets its own event.

event -> event device (or evdev?)

It is not clear from the message what HID_QUIRK_INPUT_PER_APP has to do with
renaming the devices/having one evdev vs multiple: please make
it explicit in the commit message (and perhaps make explicit if (and how),
in case it could make any difference, how programs might change
theirs behavior as a consequence).

I like the fact that userspace only sees one keyboard for what is,
effectively, one keyboard device.

The code looks good to me: make the commit message more
explanatory and I'll include my reviewed-by.

Thanks,
Denis

> When this is done, the probes are called multiple times. Due to this,
> the rgb check needs to be moved into probe, and the report fixup should
> be skipped for non-vendor endpoints (prevents multiple prints).
>
> Reviewed-by: Luke D. Jones <luke@ljones.dev>
> Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
> ---
>  drivers/hid/hid-asus.c | 59 +++++++++++++++++++++++++++---------------
>  1 file changed, 38 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 03f0d86936fc..bbbac98f76c6 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -47,6 +47,7 @@ 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
> @@ -89,6 +90,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
>  #define QUIRK_ROG_NKEY_KEYBOARD		BIT(11)
>  #define QUIRK_ROG_CLAYMORE_II_KEYBOARD BIT(12)
>  #define QUIRK_ROG_ALLY_XPAD		BIT(13)
> +#define QUIRK_SKIP_REPORT_FIXUP		BIT(14)
>  
>  #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
>  						 QUIRK_NO_INIT_REPORTS | \
> @@ -125,7 +127,6 @@ 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;
> @@ -316,7 +317,7 @@ 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",
> @@ -931,11 +932,6 @@ 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;
>  }
>  
> @@ -1008,15 +1004,6 @@ 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;
>  	}
> @@ -1133,8 +1120,10 @@ 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;
> +	int ret, is_vendor = 0;
>  
>  	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
>  	if (drvdata == NULL) {
> @@ -1218,18 +1207,42 @@ 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;
> +	}
> +
> +	/*
> +	 * For ROG keyboards, make them HID/hiddev compliant by creating one
> +	 * input per application. For interfaces other than the vendor one,
> +	 * disable report fixups.
> +	 */
> +	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
> +		if (!is_vendor)
> +			drvdata->quirks |= QUIRK_SKIP_REPORT_FIXUP;
> +		hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
> +	}
> +
>  	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
> -	 * were freed during registration due to no usages being mapped,
> -	 * leaving drvdata->input pointing to freed memory.
> +	 * For ROG keyboards, skip rename for consistency and ->input check as
> +	 * some devices do not have inputs.
>  	 */
> +	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD)
> +		return 0;
> +
>  	if (!drvdata->input || !(hdev->claimed & HID_CLAIMED_INPUT)) {
>  		hid_err(hdev, "Asus input not registered\n");
>  		ret = -ENOMEM;
> @@ -1352,6 +1365,10 @@ static const __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
>  		rdesc = new_rdesc;
>  	}
>  
> +	/* Vendor fixups should only apply to NKEY vendor devices. */
> +	if (drvdata->quirks & QUIRK_SKIP_REPORT_FIXUP)
> +		return rdesc;
> +
>  	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD &&
>  			*rsize == 331 && rdesc[190] == 0x85 && rdesc[191] == 0x5a &&
>  			rdesc[204] == 0x95 && rdesc[205] == 0x05) {