[PATCH v1 5/5] rtc: rtc-cmos: Disable ACPI RTC event on removal

Rafael J. Wysocki
2022-11-07T20:03:40Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make cmos_do_remove() drop the ACPI RTC fixed event handler so as to
prevent it from operating on stale data in case the event triggers
after driver removal.

While at it, make cmos_do_remove() also clear the driver data pointer
of the device and make cmos_acpi_wake_setup() do that in the error path
too.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/rtc/rtc-cmos.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
--- linux-pm.orig/drivers/rtc/rtc-cmos.c
+++ linux-pm/drivers/rtc/rtc-cmos.c
@@ -798,6 +798,12 @@ static inline void acpi_rtc_event_setup(
acpi_disable_event(ACPI_EVENT_RTC, 0);
}

+static inline void acpi_rtc_event_cleanup(void)
+{
+ if (!acpi_disabled)
+ acpi_remove_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler);
+}
+
static void rtc_wake_on(struct device *dev)
{
acpi_clear_event(ACPI_EVENT_RTC);
@@ -884,6 +890,10 @@ static inline void acpi_rtc_event_setup(
{
}

+static inline void acpi_rtc_event_cleanup(void)
+{
+}
+
static inline void cmos_acpi_wake_setup(struct device *dev)
{
}
@@ -1109,6 +1119,7 @@ cleanup2:
free_irq(rtc_irq, cmos_rtc.rtc);
cleanup1:
cmos_rtc.dev = NULL;
+ dev_set_drvdata(dev, NULL);
cleanup0:
if (RTC_IOMAPPED)
release_region(ports->start, resource_size(ports));
@@ -1138,6 +1149,9 @@ static void cmos_do_remove(struct device
hpet_unregister_irq_handler(cmos_interrupt);
}

+ if (!dev_get_platdata(dev))
+ acpi_rtc_event_cleanup();
+
cmos->rtc = NULL;

ports = cmos->iomem;
@@ -1148,6 +1162,7 @@ static void cmos_do_remove(struct device
cmos->iomem = NULL;

cmos->dev = NULL;
+ dev_set_drvdata(dev, NULL);
}

static int cmos_aie_poweroff(struct device *dev)