Re: [PATCH v6 1/2] platform/x86/lenovo: lenovo-ymc: Suppress probe on Yoga Book 9 14IAH10

[Mark Pearson]

On Mon, Jun 8, 2026, at 9:29 PM, Mark Pearson wrote:
> Hi Dave
>
> On Mon, Jun 8, 2026, at 5:52 PM, Dave Carey wrote:
>> The Yoga Book 9 14IAH10 (DMI product name "83KJ") has a dedicated
>> yb9-kbdock WMI driver that registers an input device reporting
>> SW_TABLET_MODE to track the detachable Bluetooth keyboard.
>>
>> lenovo-ymc also loads on this machine and creates an input node with the
>> SW_TABLET_MODE capability bit set.  For input switches, the presence of
>> the capability bit has semantic meaning: userspace (e.g. GNOME) reads
>> the switch state at startup from every node advertising the capability
>> and does not expect more than one such node.
>>
>> Add a DMI match for the Yoga Book 9 14IAH10 to probe() so that
>> lenovo-ymc returns -ENODEV on this hardware, leaving yb9-kbdock as the
>> sole SW_TABLET_MODE source.  The ymc_ec_trigger EC write, the only
>> other action taken in response to a YMC event, is guarded by a separate
>> DMI table that excludes this machine; no other functionality is affected.
>>
>> Signed-off-by: Dave Carey <carvsdriver@xxxxxxxxx>
>> ---
>>  drivers/platform/x86/lenovo/ymc.c | 19 +++++++++++++++++++
>>  1 file changed, 19 insertions(+)
>>
>> diff --git a/drivers/platform/x86/lenovo/ymc.c 
>> b/drivers/platform/x86/lenovo/ymc.c
>> --- a/drivers/platform/x86/lenovo/ymc.c
>> +++ b/drivers/platform/x86/lenovo/ymc.c
>> @@ -23,7 +23,23 @@ module_param(force, bool, 0444);
>>  static bool force;
>>  module_param(force, bool, 0444);
>>  MODULE_PARM_DESC(force, "Force loading on boards without a convertible 
>> DMI chassis-type");
>>
>> +static const struct dmi_system_id lenovo_ymc_nosupport_dmi_table[] = {
>> +	{
>> +		/*
>> +		 * Yoga Book 9 14IAH10: SW_TABLET_MODE is reported by the
>> +		 * yb9-kbdock driver.  Suppress lenovo-ymc on this machine to
>> +		 * avoid userspace seeing two input nodes that both advertise
>> +		 * the SW_TABLET_MODE capability.
>> +		 */
>> +		.matches = {
>> +			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>> +			DMI_MATCH(DMI_PRODUCT_NAME, "83KJ"),
>> +		},
>> +	},
>> +	{ }
>> +};
>> +
>>  static const struct dmi_system_id allowed_chasis_types_dmi_table[] = {
>>  	{
>>  		.matches = {
>> @@ -100,7 +116,10 @@ static int lenovo_ymc_probe(struct wmi_device 
>> *wdev, const void *ctx)
>>  	struct lenovo_ymc_private *priv;
>>  	struct input_dev *input_dev;
>>  	int err;
>>
>> +	if (dmi_check_system(lenovo_ymc_nosupport_dmi_table))
>> +		return -ENODEV;
>> +
>>  	if (!dmi_check_system(allowed_chasis_types_dmi_table)) {
>>  		if (force)
>>  			dev_info(&wdev->dev, "Force loading Lenovo YMC support\n");
>> --
>> 2.54.0
>
> I'm sure I'm missing the obvious - but where is the yb9-kbdock driver? 
> I can't find it...
>
> I was curious as to whether a separate driver was really needed for 
> this platform, or if it should have been integrated in the ymc driver 
> in the first place?
>
> Mark

Nevermind - ignore this. I just saw patch 2 and went Durrrr....
My brain is still in vacation mode :)