[PATCH v6 1/4] HID: wacom: Advertise SW_MUTE_DEVICE capability prior to registration

From: Lee Jones

Date: Thu Jul 16 2026 - 05:12:05 EST


Input subsystem guidelines require that device capabilities are advertised
before the input device is registered. The Wacom driver was violating
this by advertising the SW_MUTE_DEVICE capability post-registration in
wacom_set_shared_values() (and duplicating it in device-specific setup
cases).

Resolve this by moving the SW_MUTE_DEVICE capability setup to
wacom_setup_touch_input_capabilities() for all touch devices that support
it, excluding TabletPC devices.

Additionally, replace the lookup-dependent
'wacom_wac->shared->touch->product' references with 'hdev->product'
inside wacom_setup_touch_input_capabilities() as 'hdev' is already
available and represents the touch device itself.

Fixes: d2ec58aee8b1 ("HID: wacom: generic: support generic touch switch")
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---

v4 -> v5: New patch used to split out SW_MUTE_DEVICE as per Jason's request
v5 -> v6: Unconditionally advertise SW_MUTE_DEVICE on generic touch devices

drivers/hid/wacom_sys.c | 6 ------
drivers/hid/wacom_wac.c | 19 +++++++++++--------
2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 0eafa483b7f7..6c2a3ddfe366 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -2359,12 +2359,6 @@ static void wacom_set_shared_values(struct wacom_wac *wacom_wac)
wacom_wac->shared->is_touch_on = true;
}

- if (wacom_wac->shared->has_mute_touch_switch &&
- wacom_wac->shared->touch_input) {
- set_bit(EV_SW, wacom_wac->shared->touch_input->evbit);
- input_set_capability(wacom_wac->shared->touch_input, EV_SW,
- SW_MUTE_DEVICE);
- }
}

static int wacom_parse_and_register(struct wacom *wacom, bool wireless)
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index a29bf051ada7..32c4fd03479e 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -3953,6 +3953,8 @@ int wacom_setup_pen_input_capabilities(struct input_dev *input_dev,
int wacom_setup_touch_input_capabilities(struct input_dev *input_dev,
struct wacom_wac *wacom_wac)
{
+ struct wacom *wacom = container_of(wacom_wac, struct wacom, wacom_wac);
+ struct hid_device *hdev = wacom->hdev;
struct wacom_features *features = &wacom_wac->features;

if (!(features->device_type & WACOM_DEVICETYPE_TOUCH))
@@ -3963,9 +3965,12 @@ int wacom_setup_touch_input_capabilities(struct input_dev *input_dev,
else
__set_bit(INPUT_PROP_POINTER, input_dev->propbit);

- if (features->type == HID_GENERIC)
+ if (features->type == HID_GENERIC) {
+ input_dev->evbit[0] |= BIT_MASK(EV_SW);
+ __set_bit(SW_MUTE_DEVICE, input_dev->swbit);
/* setup has already been done */
return 0;
+ }

input_dev->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
__set_bit(BTN_TOUCH, input_dev->keybit);
@@ -3997,19 +4002,17 @@ int wacom_setup_touch_input_capabilities(struct input_dev *input_dev,
input_dev->evbit[0] |= BIT_MASK(EV_SW);
__set_bit(SW_MUTE_DEVICE, input_dev->swbit);

- if (wacom_wac->shared->touch->product == 0x361) {
+ if (hdev->product == 0x361) {
input_set_abs_params(input_dev, ABS_MT_POSITION_X,
0, 12440, 4, 0);
input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
0, 8640, 4, 0);
- }
- else if (wacom_wac->shared->touch->product == 0x360) {
+ } else if (hdev->product == 0x360) {
input_set_abs_params(input_dev, ABS_MT_POSITION_X,
0, 8960, 4, 0);
input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
0, 5920, 4, 0);
- }
- else if (wacom_wac->shared->touch->product == 0x393) {
+ } else if (hdev->product == 0x393) {
input_set_abs_params(input_dev, ABS_MT_POSITION_X,
0, 6400, 4, 0);
input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
@@ -4039,8 +4042,8 @@ int wacom_setup_touch_input_capabilities(struct input_dev *input_dev,
fallthrough;

case WACOM_27QHDT:
- if (wacom_wac->shared->touch->product == 0x32C ||
- wacom_wac->shared->touch->product == 0xF6) {
+ if (hdev->product == 0x32C ||
+ hdev->product == 0xF6) {
input_dev->evbit[0] |= BIT_MASK(EV_SW);
__set_bit(SW_MUTE_DEVICE, input_dev->swbit);
wacom_wac->has_mute_touch_switch = true;
--
2.55.0.141.g00534a21ce-goog