Re: [PATCH v2 1/2] platform/x86: bitland-mifs-wmi: Add Xiaomi Book Pro 14 quirk

[Mingyou Chen <qby140326@gmail.com>]

On 10/26/26 03:54, Chris Taraszka wrote:
> The Xiaomi Book Pro 14 (board TM2424) implements SystemPerMode with
> its own values. Its firmware ignores 0x00 and 0x01, and GET returns one
> of 0x02, 0x03, 0x04, 0x09 or 0x0a, so with the default table balanced
> and balanced-performance are no-ops and reading the profile fails with
> -EINVAL whenever the firmware is in 0x04, 0x09 or 0x0a. The failed read
> also aborts system suspend.
>
> The values were identified from the WMAA method in the firmware's SSDT
> and by setting each one and reading the sustained package power limit
> from intel-rapl-mmio on AC:
>
>    0x02  18 W
>    0x03  37 W
>    0x09  45 W
>    0x04  58 W
>    0x0a  18 W
>
> Map low-power, balanced, balanced-performance and performance to 0x02,
> 0x03, 0x09 and 0x04. 0x0a is only entered through the firmware's own
> mode cycling, so report it as low-power without offering it for SET.
>
> The machine is USB-C only and WMI_FN_SYSTEM_AC_TYPE is not implemented,
> so skip the AC type check.
>
> Signed-off-by: Chris Taraszka <chris@miget.com>
> ---
>
> Notes:
>      Tested on the Xiaomi Book Pro 14 (TM2424, BIOS XMAPT4B0P0A0A) with this
>      series on top of v13, backported to v7.3, on AC: all four profiles set
>      and read back, and the firmware mode (EC 0x68) and PL1 follow:
>      0x02/18 W, 0x03/37 W, 0x09/45 W, 0x04/58 W. These match the values
>      first measured on BIOS XMAPT4B0P0909. s2idle suspend/resume from
>      performance restores 0x04.
>      
>      On battery, balanced-performance and performance are refused by
>      bitland_pp_check_capability(), although BIOS 0909 applies 0x04 on
>      battery. This patch leaves that check as it is.
>
>   drivers/platform/x86/bitland-mifs-wmi.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
>
> diff --git a/drivers/platform/x86/bitland-mifs-wmi.c b/drivers/platform/x86/bitland-mifs-wmi.c
> index a4c341ffbb9b..73be63146fd5 100644
> --- a/drivers/platform/x86/bitland-mifs-wmi.c
> +++ b/drivers/platform/x86/bitland-mifs-wmi.c
> @@ -116,7 +116,28 @@ static const struct bitland_mifs_quirks default_quirks = {
>   	.num_profile_entries = ARRAY_SIZE(default_profile_entries),
>   };
>   
> +static const struct bitland_profile_entry tm2424_profile_entries[] = {
> +	{ PLATFORM_PROFILE_LOW_POWER,              0x02 },
> +	{ PLATFORM_PROFILE_LOW_POWER,              0x0a, true },
> +	{ PLATFORM_PROFILE_BALANCED,               0x03 },
> +	{ PLATFORM_PROFILE_BALANCED_PERFORMANCE,   0x09 },
> +	{ PLATFORM_PROFILE_PERFORMANCE,            0x04 },
> +};
> +
> +static const struct bitland_mifs_quirks tm2424_quirks = {
> +	.profile_entries = tm2424_profile_entries,
> +	.num_profile_entries = ARRAY_SIZE(tm2424_profile_entries),
> +	.skip_ac_type_check = true,
> +};
> +
>   static const struct dmi_system_id bitland_mifs_dmi_table[] = {
> +	{
> +		.matches = {
> +			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "XIAOMI"),
> +			DMI_EXACT_MATCH(DMI_BOARD_NAME, "TM2424"),
> +		},
> +		.driver_data = (void *)&tm2424_quirks,
> +	},
>   	{}
>   };
>   
Reviewed-by: Mingyou Chen <qby140326@gmail.com>