Use ACPI for RTC Alarm only for Intel platforms
1. with Low Power S0 support
2. with HPET RTC emulation enabled
3. no earlier than 2015
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/rtc/rtc-cmos.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index bcf86e1..414b450 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -43,6 +43,8 @@
#include <linux/of_platform.h>
#ifdef CONFIG_X86
#include <asm/i8259.h>
+#include <asm/cpu_device_id.h>
+#include <linux/dmi.h>
#endif
/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
@@ -1183,6 +1185,33 @@ static void rtc_wake_off(struct device *dev)
acpi_disable_event(ACPI_EVENT_RTC, 0);
}
+#ifdef CONFIG_X86
+static const struct x86_cpu_id use_acpi_alarm_ids[] = {
+ { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ANY },
+ {}
+};
+
+/* Enable use_acpi_alarm mode for Intel platforms no earlier than 2015 */
+static void use_acpi_alarm_quirks(void)
+{
+ int year;
+
+ if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
+ return;
+
+ if (!is_hpet_enabled())
+ return;
+
+ if (!x86_match_cpu(use_acpi_alarm_ids))
+ return;
+
+ if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year >= 2015)
+ use_acpi_alarm = true;
+}
+#else
+static inline void use_acpi_alarm_quirks(void) { }
+#endif
+
/* Every ACPI platform has a mc146818 compatible "cmos rtc". Here we find
* its device node and pass extra config data. This helps its driver use
* capabilities that the now-obsolete mc146818 didn't have, and informs it
@@ -1195,6 +1224,8 @@ static void cmos_wake_setup(struct device *dev)
if (acpi_disabled)
return;
+ use_acpi_alarm_quirks();
+
rtc_wake_setup(dev);
acpi_rtc_info.wake_on = rtc_wake_on;
acpi_rtc_info.wake_off = rtc_wake_off;
--
2.7.4
