rtc: cmos: Disable ACPI RTC event on removal

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.

Fixes: 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/2224609.iZASKD2KPV@kreacher
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 039486bfedf48251581bb160aba78adde5d3c478..00e2ca7374ecfb2579ed14445434d9cd6c626fe5 100644 (file)
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -798,6 +798,14 @@ static void acpi_rtc_event_setup(struct device *dev)
        acpi_disable_event(ACPI_EVENT_RTC, 0);
 }
 
+static void acpi_rtc_event_cleanup(void)
+{
+       if (acpi_disabled)
+               return;
+
+       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 +892,10 @@ static inline void acpi_rtc_event_setup(struct device *dev)
 {
 }
 
+static inline void acpi_rtc_event_cleanup(void)
+{
+}
+
 static inline void acpi_cmos_wake_setup(struct device *dev)
 {
 }
@@ -1138,6 +1150,9 @@ static void cmos_do_remove(struct device *dev)
                        hpet_unregister_irq_handler(cmos_interrupt);
        }
 
+       if (!dev_get_platdata(dev))
+               acpi_rtc_event_cleanup();
+
        cmos->rtc = NULL;
 
        ports = cmos->iomem;