Re: [PATCH 2/5] platform/x86: hp-wmi: handle firmware errors in tablet mode query

[Ilpo Järvinen]

On Thu, 16 Jul 2026, Emre Cecanpunar wrote:

> hp_wmi_get_tablet_mode() accepts any nonnegative return value from
> hp_wmi_perform_query() as success. HP firmware errors are positive, so a
> rejected query makes the zeroed response look like laptop mode.

Does this problem actually happen with some hw? Please add the info.

> Treat every nonzero result as an error and preserve negative transport
> errors. The event and resume paths pass the result directly to the input
> subsystem, where a negative errno would look like an asserted switch, so
> skip the switch update when the query fails.
>
> Fixes: 520ee4ea1cc6 ("platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method")
> Signed-off-by: Emre Cecanpunar <emreleno@xxxxxxxxx>
> ---
>  drivers/platform/x86/hp/hp-wmi.c | 26 +++++++++++++++++---------
>  1 file changed, 17 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
> index 205a6020e9c5..e226b772ef00 100644
> --- a/drivers/platform/x86/hp/hp-wmi.c
> +++ b/drivers/platform/x86/hp/hp-wmi.c
> @@ -798,8 +798,8 @@ static int hp_wmi_get_tablet_mode(void)
>  	ret = hp_wmi_perform_query(HPWMI_SYSTEM_DEVICE_MODE, HPWMI_READ,
>  				   system_device_mode, zero_if_sup(system_device_mode),
>  				   sizeof(system_device_mode));
> -	if (ret < 0)
> -		return ret;
> +	if (ret)
> +		return ret < 0 ? ret : -EINVAL;

Please use 2 separate ifs for clarity.

>  	return system_device_mode[0] == DEVICE_MODE_TABLET;
>  }
> @@ -1198,7 +1198,7 @@ static void hp_wmi_notify(union acpi_object *obj, void *context)
>  {
>  	u32 event_id, event_data;
>  	u32 *location;
> -	int key_code;
> +	int key_code, state;
>  
>  	if (!obj)
>  		return;
> @@ -1228,9 +1228,12 @@ static void hp_wmi_notify(union acpi_object *obj, void *context)
>  		if (test_bit(SW_DOCK, hp_wmi_input_dev->swbit))
>  			input_report_switch(hp_wmi_input_dev, SW_DOCK,
>  					    hp_wmi_get_dock_state());
> -		if (test_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit))
> -			input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
> -					    hp_wmi_get_tablet_mode());
> +		if (test_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit)) {
> +			state = hp_wmi_get_tablet_mode();
> +			if (state >= 0)
> +				input_report_switch(hp_wmi_input_dev,
> +						    SW_TABLET_MODE, state);

Braces are needed for multiline constructs...

...BUT, it looks there's some copy pasting going on so moving these into a 
helper both this and hp_wmi_resume_handler() could use would seem useful 
(in a preparatory patch). It would help with the line length so this may 
no longer require multiple lines with less indent.

> +		}
>  		input_sync(hp_wmi_input_dev);
>  		break;
>  	case HPWMI_PARK_HDD:
> @@ -2431,6 +2434,8 @@ static void __exit hp_wmi_bios_remove(struct platform_device *device)
>  
>  static int hp_wmi_resume_handler(struct device *device)
>  {
> +	int state;
> +
>  	/*
>  	 * Hardware state may have changed while suspended, so trigger
>  	 * input events for the current state. As this is a switch,
> @@ -2441,9 +2446,12 @@ static int hp_wmi_resume_handler(struct device *device)
>  		if (test_bit(SW_DOCK, hp_wmi_input_dev->swbit))
>  			input_report_switch(hp_wmi_input_dev, SW_DOCK,
>  					    hp_wmi_get_dock_state());
> -		if (test_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit))
> -			input_report_switch(hp_wmi_input_dev, SW_TABLET_MODE,
> -					    hp_wmi_get_tablet_mode());
> +		if (test_bit(SW_TABLET_MODE, hp_wmi_input_dev->swbit)) {
> +			state = hp_wmi_get_tablet_mode();
> +			if (state >= 0)
> +				input_report_switch(hp_wmi_input_dev,
> +						    SW_TABLET_MODE, state);
> +		}
>  		input_sync(hp_wmi_input_dev);
>  	}
>  
> 

-- 
 i.