ACPI / PM: Introduce efi poweroff for HW-full platforms without _S5

The problem is Linux registers pm_power_off = efi_power_off only if
we are in hardware reduced mode. Actually, what we also want is to do
this when ACPI S5 is simply not supported on non-legacy platforms.
Since some future Intel platforms are HW-full mode where the DSDT
fails to supply an _S5 object(without SLP_TYP), we should let such
kind of platform to leverage efi runtime service to poweroff.

This patch uses efi power off as first choice when S5 is unavailable,
even if there is a customized poweroff(driver provided, eg).
Meanwhile, the legacy platforms will not be affected because there is
no path for them to overwrite the pm_power_off to efi power off.

Suggested-by: Len Brown <len.brown@intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index ab50ada1d56e4f87f6fff3207995ea32312fb37b..818d12ad77619b8823ca8a5198c4103cf4aa0eb4 100644 (file)
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -373,5 +373,5 @@ bool efi_reboot_required(void)
 
 bool efi_poweroff_required(void)
 {
-       return !!acpi_gbl_reduced_hardware;
+       return acpi_gbl_reduced_hardware || acpi_no_s5;
 }

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 2a8b5964429753b212a0f28ff9be5f19a7a1b777..7a2e4d45b266724c536ce87361c7eb1a2a6e007c 100644 (file)
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -26,6 +26,11 @@
 #include "internal.h"
 #include "sleep.h"
 
+/*
+ * Some HW-full platforms do not have _S5, so they may need
+ * to leverage efi power off for a shutdown.
+ */
+bool acpi_no_s5;
 static u8 sleep_states[ACPI_S_STATE_COUNT];
 
 static void acpi_sleep_tts_switch(u32 acpi_state)
@@ -882,6 +887,8 @@ int __init acpi_sleep_init(void)
                sleep_states[ACPI_STATE_S5] = 1;
                pm_power_off_prepare = acpi_power_off_prepare;
                pm_power_off = acpi_power_off;
+       } else {
+               acpi_no_s5 = true;
        }
 
        supported[0] = 0;

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 06ed7e54033e7ae5554e41461a51ca0be250695f..4d2e67f633b60e088d0ccc04554f6784c482a52e 100644 (file)
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -278,6 +278,7 @@ void acpi_irq_stats_init(void);
 extern u32 acpi_irq_handled;
 extern u32 acpi_irq_not_handled;
 extern unsigned int acpi_sci_irq;
+extern bool acpi_no_s5;
 #define INVALID_ACPI_IRQ       ((unsigned)-1)
 static inline bool acpi_sci_irq_valid(void)
 {