[PATCH 6.0 0789/1073] rtc: cmos: Disable ACPI RTC event on removal

Greg Kroah-Hartman
2022-12-28T16:33:43Z

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

[ Upstream commit 83ebb7b3036d151ee39a4a752018665648fc3bd4 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/rtc/rtc-cmos.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 039486bfedf4..00e2ca7374ec 100644
--- 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;
--
2.35.1