Re: [RFC v1 2/8] acpi/x86: s2idle: Rename LPS0 constants so they mirror their function

[Rafael J. Wysocki]

On Fri, Dec 26, 2025 at 11:27 AM Antheas Kapenekakis <lkml@xxxxxxxxxxx> wrote:
>
> The LPS0 3/4 constants are part of a firmware notification called
> "Display on/off", in which the device enters a "Screen Off" state.
> The LPS0 7/8 constants are part of a firmware notification in which
> a Windows modern standby computer enters a "sleep" state where the
> CPU may still be active and maintain the radios.
>
> However, currently, the values are named as "Screen on/off"

This is based on the Intel documentation:
https://uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf

> and "MS entry/exit", where Modern Standby is abbreviated as "MS". Therefore,
> perform a minor rename so that the values match their function.

I'm not sure about the first two at least.

> Then, fix the debug message to say that it executes notifications instead of
> entering states as it is otherwise confusing.
>
> Signed-off-by: Antheas Kapenekakis <lkml@xxxxxxxxxxx>
> ---
>  drivers/acpi/x86/s2idle.c | 54 +++++++++++++++++++--------------------
>  1 file changed, 27 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
> index 6d4d06236f61..1f13c8b0ef83 100644
> --- a/drivers/acpi/x86/s2idle.c
> +++ b/drivers/acpi/x86/s2idle.c
> @@ -39,19 +39,19 @@ static const struct acpi_device_id lps0_device_ids[] = {
>  #define ACPI_LPS0_DSM_UUID     "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
>
>  #define ACPI_LPS0_GET_DEVICE_CONSTRAINTS       1
> -#define ACPI_LPS0_SCREEN_OFF   3
> -#define ACPI_LPS0_SCREEN_ON    4
> +#define ACPI_LPS0_DISPLAY_OFF  3
> +#define ACPI_LPS0_DISPLAY_ON   4
>  #define ACPI_LPS0_ENTRY                5
>  #define ACPI_LPS0_EXIT         6
> -#define ACPI_LPS0_MS_ENTRY      7
> -#define ACPI_LPS0_MS_EXIT       8
> +#define ACPI_LPS0_SLEEP_ENTRY  7
> +#define ACPI_LPS0_SLEEP_EXIT   8

These two renames are fine with me, although I'm not sure if they are
worth the hassle.

>
>  /* AMD */
>  #define ACPI_LPS0_DSM_UUID_AMD      "e3f32452-febc-43ce-9039-932122d37721"
>  #define ACPI_LPS0_ENTRY_AMD         2
>  #define ACPI_LPS0_EXIT_AMD          3
> -#define ACPI_LPS0_SCREEN_OFF_AMD    4
> -#define ACPI_LPS0_SCREEN_ON_AMD     5
> +#define ACPI_LPS0_DISPLAY_OFF_AMD   4
> +#define ACPI_LPS0_DISPLAY_ON_AMD    5
>
>  static acpi_handle lps0_device_handle;
>  static guid_t lps0_dsm_guid;
> @@ -340,25 +340,25 @@ static const char *acpi_sleep_dsm_state_to_str(unsigned int state)
>  {
>         if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) {
>                 switch (state) {
> -               case ACPI_LPS0_SCREEN_OFF:
> -                       return "screen off";
> -               case ACPI_LPS0_SCREEN_ON:
> -                       return "screen on";
> +               case ACPI_LPS0_DISPLAY_OFF:
> +                       return "display off";
> +               case ACPI_LPS0_DISPLAY_ON:
> +                       return "display on";
>                 case ACPI_LPS0_ENTRY:
>                         return "lps0 entry";
>                 case ACPI_LPS0_EXIT:
>                         return "lps0 exit";
> -               case ACPI_LPS0_MS_ENTRY:
> -                       return "lps0 ms entry";
> -               case ACPI_LPS0_MS_EXIT:
> -                       return "lps0 ms exit";
> +               case ACPI_LPS0_SLEEP_ENTRY:
> +                       return "sleep entry";
> +               case ACPI_LPS0_SLEEP_EXIT:
> +                       return "sleep exit";
>                 }
>         } else {
>                 switch (state) {
> -               case ACPI_LPS0_SCREEN_ON_AMD:
> -                       return "screen on";
> -               case ACPI_LPS0_SCREEN_OFF_AMD:
> -                       return "screen off";
> +               case ACPI_LPS0_DISPLAY_ON_AMD:
> +                       return "display on";
> +               case ACPI_LPS0_DISPLAY_OFF_AMD:
> +                       return "display off";
>                 case ACPI_LPS0_ENTRY_AMD:
>                         return "lps0 entry";
>                 case ACPI_LPS0_EXIT_AMD:
> @@ -383,7 +383,7 @@ static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, g
>         lps0_dsm_state = func;
>         if (pm_debug_messages_on) {
>                 acpi_handle_info(lps0_device_handle,
> -                               "%s transitioned to state %s\n",
> +                               "%s executed notification %s\n",
>                                  out_obj ? "Successfully" : "Failed to",
>                                  acpi_sleep_dsm_state_to_str(lps0_dsm_state));
>         }
> @@ -545,12 +545,12 @@ static int acpi_s2idle_prepare_late_lps0(void)
>         /* Screen off */
>         if (lps0_dsm_func_mask > 0)
>                 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
> -                                       ACPI_LPS0_SCREEN_OFF_AMD :
> -                                       ACPI_LPS0_SCREEN_OFF,
> +                                       ACPI_LPS0_DISPLAY_OFF_AMD :
> +                                       ACPI_LPS0_DISPLAY_OFF,
>                                         lps0_dsm_func_mask, lps0_dsm_guid);
>
>         if (lps0_dsm_func_mask_microsoft > 0)
> -               acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
> +               acpi_sleep_run_lps0_dsm(ACPI_LPS0_DISPLAY_OFF,
>                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
>
>         /* LPS0 entry */
> @@ -560,7 +560,7 @@ static int acpi_s2idle_prepare_late_lps0(void)
>
>         if (lps0_dsm_func_mask_microsoft > 0) {
>                 /* Modern Standby entry */
> -               acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
> +               acpi_sleep_run_lps0_dsm(ACPI_LPS0_SLEEP_ENTRY,
>                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
>                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
>                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
> @@ -613,18 +613,18 @@ static void acpi_s2idle_restore_early_lps0(void)
>                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
>                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
>                 /* Modern Standby exit */
> -               acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
> +               acpi_sleep_run_lps0_dsm(ACPI_LPS0_SLEEP_EXIT,
>                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
>         }
>
>         /* Screen on */
>         if (lps0_dsm_func_mask_microsoft > 0)
> -               acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
> +               acpi_sleep_run_lps0_dsm(ACPI_LPS0_DISPLAY_ON,
>                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
>         if (lps0_dsm_func_mask > 0)
>                 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
> -                                       ACPI_LPS0_SCREEN_ON_AMD :
> -                                       ACPI_LPS0_SCREEN_ON,
> +                                       ACPI_LPS0_DISPLAY_ON_AMD :
> +                                       ACPI_LPS0_DISPLAY_ON,
>                                         lps0_dsm_func_mask, lps0_dsm_guid);
>  }
>
> --
> 2.52.0
>
>
>