rtc: rtc-cmos: Assorted ACPI-related cleanups and fixes

PATCH Applied Rafael J. Wysocki 4 participants 9 messages Nov 9, 2022 – Nov 15, 2022

Subsystems (2)

ACPI Real time clock (RTC)

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Rafael J. Wysocki

author

2022-11-09 12:16 UTC #0 lore raw

v2 cover rtc: rtc-cmos: Assorted ACPI-related cleanups and fixes

Hi All,

This is a v2 of the series previously posted as

https://lore.kernel.org/linux-acpi/2276401.ElGaqSPkdT@kreacher/

The first three patches in the series have not changed since then (I have considered moving the last patch, which is a fix, to the front, but that turns out to be a bit cumbersome and not really worth the effort).

This series of patches does some assorted ACPI-related cleanups to the CMOS RTC driver:
- redundant static variable is dropped,
- code duplication is reduced,
- code is relocated so as to drop a few unnecessary forward declarations of functions,
- functions are renamed to avoid confusion,
and fixes up an issue in the driver removal path.

Thanks!

Rafael J. Wysocki

author

2022-11-09 12:16 UTC #1 lore raw

PATCH v2 1/5 rtc: rtc-cmos: Call cmos_wake_setup() from cmos_do_probe()

From: Rafael J. Wysocki <[email protected]>

Notice that cmos_wake_setup() is the only user of acpi_rtc_info and it can operate on the cmos_rtc variable directly, so it need not set the platform_data pointer before cmos_do_probe() is called. Instead, it can be called by cmos_do_probe() in the case when the platform_data pointer is not set to implement the default behavior (which is to use the FADT information as long as ACPI support is enabled).

Modify the code accordingly.

While at it, drop a comment that doesn't really match the code it is supposed to be describing.

Signed-off-by Rafael J. Wysocki <[email protected]>

---

No changes since v1.

---
 drivers/rtc/rtc-cmos.c |   47 ++++++++++++++++++++++-------------------------
 1 file changed, 22 insertions(+), 25 deletions(-)

drivers/rtc/rtc-cmos.c +22 ~~-25~~

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
@@ -744,6 +744,8 @@ static irqreturn_t cmos_interrupt(int ir
 		return IRQ_NONE;
 }
 
+static void cmos_wake_setup(struct device *dev);
+
 #ifdef	CONFIG_PNP
 #define	INITSECTION

@@ -827,19 +829,27 @@ cmos_do_probe(struct device *dev, struct
 		if (info->address_space)
 			address_space = info->address_space;
 
-		if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
-			cmos_rtc.day_alrm = info->rtc_day_alarm;
-		if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
-			cmos_rtc.mon_alrm = info->rtc_mon_alarm;
-		if (info->rtc_century && info->rtc_century < 128)
-			cmos_rtc.century = info->rtc_century;
+		cmos_rtc.day_alrm = info->rtc_day_alarm;
+		cmos_rtc.mon_alrm = info->rtc_mon_alarm;
+		cmos_rtc.century = info->rtc_century;
 
 		if (info->wake_on && info->wake_off) {
 			cmos_rtc.wake_on = info->wake_on;
 			cmos_rtc.wake_off = info->wake_off;
 		}
+	} else {
+		cmos_wake_setup(dev);
 	}
 
+	if (cmos_rtc.day_alrm >= 128)
+		cmos_rtc.day_alrm = 0;
+
+	if (cmos_rtc.mon_alrm >= 128)
+		cmos_rtc.mon_alrm = 0;
+
+	if (cmos_rtc.century >= 128)
+		cmos_rtc.century = 0;
+
 	cmos_rtc.dev = dev;
 	dev_set_drvdata(dev, &cmos_rtc);

@@ -1275,13 +1285,6 @@ static void use_acpi_alarm_quirks(void)
 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
- * that this board's RTC is wakeup-capable (per ACPI spec).
- */
-static struct cmos_rtc_board_info acpi_rtc_info;
-
 static void cmos_wake_setup(struct device *dev)
 {
 	if (acpi_disabled)

@@ -1289,26 +1292,23 @@ static void cmos_wake_setup(struct devic
 
 	use_acpi_alarm_quirks();
 
-	acpi_rtc_info.wake_on = rtc_wake_on;
-	acpi_rtc_info.wake_off = rtc_wake_off;
+	cmos_rtc.wake_on = rtc_wake_on;
+	cmos_rtc.wake_off = rtc_wake_off;
 
-	/* workaround bug in some ACPI tables */
+	/* ACPI tables bug workaround. */
 	if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
 		dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
 			acpi_gbl_FADT.month_alarm);
 		acpi_gbl_FADT.month_alarm = 0;
 	}
 
-	acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
-	acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
-	acpi_rtc_info.rtc_century = acpi_gbl_FADT.century;
+	cmos_rtc.day_alrm = acpi_gbl_FADT.day_alarm;
+	cmos_rtc.mon_alrm = acpi_gbl_FADT.month_alarm;
+	cmos_rtc.century = acpi_gbl_FADT.century;
 
-	/* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
 	if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
 		dev_info(dev, "RTC can wake from S4\n");
 
-	dev->platform_data = &acpi_rtc_info;
-
 	/* RTC always wakes from S1/S2/S3, and often S4/STD */
 	device_init_wakeup(dev, 1);
 }

@@ -1359,8 +1359,6 @@ static int cmos_pnp_probe(struct pnp_dev
 {
 	int irq, ret;
 
-	cmos_wake_setup(&pnp->dev);
-
 	if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
 		irq = 0;
 #ifdef CONFIG_X86

@@ -1468,7 +1466,6 @@ static int __init cmos_platform_probe(st
 	int irq, ret;
 
 	cmos_of_init(pdev);
-	cmos_wake_setup(&pdev->dev);
 
 	if (RTC_IOMAPPED)
 		resource = platform_get_resource(pdev, IORESOURCE_IO, 0);

Rafael J. Wysocki

author

2022-11-09 12:15 UTC #2 lore raw

PATCH v2 2/5 rtc: rtc-cmos: Call rtc_wake_setup() from cmos_do_probe()

In reply to Rafael J. Wysocki

From: Rafael J. Wysocki <[email protected]>

To reduce code duplication, move the invocation of rtc_wake_setup() into cmos_do_probe() and simplify the callers of the latter.

No intentional functional impact.

Signed-off-by Rafael J. Wysocki <[email protected]>

---

No changes since v1.

---
 drivers/rtc/rtc-cmos.c |   28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

drivers/rtc/rtc-cmos.c +12 ~~-16~~

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
@@ -744,6 +744,7 @@ static irqreturn_t cmos_interrupt(int ir
 		return IRQ_NONE;
 }
 
+static inline void rtc_wake_setup(struct device *dev);
 static void cmos_wake_setup(struct device *dev);
 
 #ifdef	CONFIG_PNP

@@ -938,6 +939,13 @@ cmos_do_probe(struct device *dev, struct
 	nvmem_cfg.size = address_space - NVRAM_OFFSET;
 	devm_rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg);
 
+	/*
+	 * Everything has gone well so far, so by default register a handler for
+	 * the ACPI RTC fixed event.
+	 */
+	if (!info)
+		rtc_wake_setup(dev);
+
 	dev_info(dev, "%s%s, %d bytes nvram%s\n",
 		 !is_valid_irq(rtc_irq) ? "no alarms" :
 		 cmos_rtc.mon_alrm ? "alarms up to one year" :

@@ -1357,7 +1365,7 @@ static void rtc_wake_setup(struct device
 
 static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 {
-	int irq, ret;
+	int irq;
 
 	if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
 		irq = 0;

@@ -1373,13 +1381,7 @@ static int cmos_pnp_probe(struct pnp_dev
 		irq = pnp_irq(pnp, 0);
 	}
 
-	ret = cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
-	if (ret)
-		return ret;
-
-	rtc_wake_setup(&pnp->dev);
-
-	return 0;
+	return cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
 }
 
 static void cmos_pnp_remove(struct pnp_dev *pnp)

@@ -1463,7 +1465,7 @@ static inline void cmos_of_init(struct p
 static int __init cmos_platform_probe(struct platform_device *pdev)
 {
 	struct resource *resource;
-	int irq, ret;
+	int irq;
 
 	cmos_of_init(pdev);

@@ -1475,13 +1477,7 @@ static int __init cmos_platform_probe(st
 	if (irq < 0)
 		irq = -1;
 
-	ret = cmos_do_probe(&pdev->dev, resource, irq);
-	if (ret)
-		return ret;
-
-	rtc_wake_setup(&pdev->dev);
-
-	return 0;
+	return cmos_do_probe(&pdev->dev, resource, irq);
 }
 
 static int cmos_platform_remove(struct platform_device *pdev)

Rafael J. Wysocki

author

2022-11-09 12:15 UTC #3 lore raw

PATCH v2 3/5 rtc: rtc-cmos: Eliminate forward declarations of some functions

In reply to Rafael J. Wysocki

From: Rafael J. Wysocki <[email protected]>
Subject: [PATCH] rtc: rtc-cmos:

Reorder the ACPI-related code before cmos_do_probe() so as to eliminate excessive forward declarations of some functions.

While at it, for consistency, add the inline modifier to the definitions of empty stub static funtions and remove it from the corresponding definitions of functions with non-empty bodies.

No intentional functional impact.

Signed-off-by Rafael J. Wysocki <[email protected]>

---

No changes since v1.

---
 drivers/rtc/rtc-cmos.c |  304 ++++++++++++++++++++++++-------------------------
 1 file changed, 149 insertions(+), 155 deletions(-)

drivers/rtc/rtc-cmos.c +149 ~~-155~~

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
@@ -744,8 +744,155 @@ static irqreturn_t cmos_interrupt(int ir
 		return IRQ_NONE;
 }
 
-static inline void rtc_wake_setup(struct device *dev);
-static void cmos_wake_setup(struct device *dev);
+#ifdef	CONFIG_ACPI
+
+#include <linux/acpi.h>
+
+static u32 rtc_handler(void *context)
+{
+	struct device *dev = context;
+	struct cmos_rtc *cmos = dev_get_drvdata(dev);
+	unsigned char rtc_control = 0;
+	unsigned char rtc_intr;
+	unsigned long flags;
+
+
+	/*
+	 * Always update rtc irq when ACPI is used as RTC Alarm.
+	 * Or else, ACPI SCI is enabled during suspend/resume only,
+	 * update rtc irq in that case.
+	 */
+	if (cmos_use_acpi_alarm())
+		cmos_interrupt(0, (void *)cmos->rtc);
+	else {
+		/* Fix me: can we use cmos_interrupt() here as well? */
+		spin_lock_irqsave(&rtc_lock, flags);
+		if (cmos_rtc.suspend_ctrl)
+			rtc_control = CMOS_READ(RTC_CONTROL);
+		if (rtc_control & RTC_AIE) {
+			cmos_rtc.suspend_ctrl &= ~RTC_AIE;
+			CMOS_WRITE(rtc_control, RTC_CONTROL);
+			rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
+			rtc_update_irq(cmos->rtc, 1, rtc_intr);
+		}
+		spin_unlock_irqrestore(&rtc_lock, flags);
+	}
+
+	pm_wakeup_hard_event(dev);
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+	return ACPI_INTERRUPT_HANDLED;
+}
+
+static void rtc_wake_setup(struct device *dev)
+{
+	if (acpi_disabled)
+		return;
+
+	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
+	/*
+	 * After the RTC handler is installed, the Fixed_RTC event should
+	 * be disabled. Only when the RTC alarm is set will it be enabled.
+	 */
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+}
+
+static void rtc_wake_on(struct device *dev)
+{
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_enable_event(ACPI_EVENT_RTC, 0);
+}
+
+static void rtc_wake_off(struct device *dev)
+{
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+}
+
+#ifdef CONFIG_X86
+/* Enable use_acpi_alarm mode for Intel platforms no earlier than 2015 */
+static void use_acpi_alarm_quirks(void)
+{
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+		return;
+
+	if (!is_hpet_enabled())
+		return;
+
+	if (dmi_get_bios_year() < 2015)
+		return;
+
+	use_acpi_alarm = true;
+}
+#else
+static inline void use_acpi_alarm_quirks(void) { }
+#endif
+
+static void cmos_wake_setup(struct device *dev)
+{
+	if (acpi_disabled)
+		return;
+
+	use_acpi_alarm_quirks();
+
+	cmos_rtc.wake_on = rtc_wake_on;
+	cmos_rtc.wake_off = rtc_wake_off;
+
+	/* ACPI tables bug workaround. */
+	if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
+		dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
+			acpi_gbl_FADT.month_alarm);
+		acpi_gbl_FADT.month_alarm = 0;
+	}
+
+	cmos_rtc.day_alrm = acpi_gbl_FADT.day_alarm;
+	cmos_rtc.mon_alrm = acpi_gbl_FADT.month_alarm;
+	cmos_rtc.century = acpi_gbl_FADT.century;
+
+	if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
+		dev_info(dev, "RTC can wake from S4\n");
+
+	/* RTC always wakes from S1/S2/S3, and often S4/STD */
+	device_init_wakeup(dev, 1);
+}
+
+static void cmos_check_acpi_rtc_status(struct device *dev,
+					      unsigned char *rtc_control)
+{
+	struct cmos_rtc *cmos = dev_get_drvdata(dev);
+	acpi_event_status rtc_status;
+	acpi_status status;
+
+	if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
+		return;
+
+	status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "Could not get RTC status\n");
+	} else if (rtc_status & ACPI_EVENT_FLAG_SET) {
+		unsigned char mask;
+		*rtc_control &= ~RTC_AIE;
+		CMOS_WRITE(*rtc_control, RTC_CONTROL);
+		mask = CMOS_READ(RTC_INTR_FLAGS);
+		rtc_update_irq(cmos->rtc, 1, mask);
+	}
+}
+
+#else /* !CONFIG_ACPI */
+
+static inline void rtc_wake_setup(struct device *dev)
+{
+}
+
+static inline void cmos_wake_setup(struct device *dev)
+{
+}
+
+static inline void cmos_check_acpi_rtc_status(struct device *dev,
+					      unsigned char *rtc_control)
+{
+}
+#endif /* CONFIG_ACPI */
 
 #ifdef	CONFIG_PNP
 #define	INITSECTION

@@ -1140,9 +1287,6 @@ static void cmos_check_wkalrm(struct dev
 	}
 }
 
-static void cmos_check_acpi_rtc_status(struct device *dev,
-				       unsigned char *rtc_control);
-
 static int __maybe_unused cmos_resume(struct device *dev)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);

@@ -1209,156 +1353,6 @@ static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cm
  * predate even PNPBIOS should set up platform_bus devices.
  */
 
-#ifdef	CONFIG_ACPI
-
-#include <linux/acpi.h>
-
-static u32 rtc_handler(void *context)
-{
-	struct device *dev = context;
-	struct cmos_rtc *cmos = dev_get_drvdata(dev);
-	unsigned char rtc_control = 0;
-	unsigned char rtc_intr;
-	unsigned long flags;
-
-
-	/*
-	 * Always update rtc irq when ACPI is used as RTC Alarm.
-	 * Or else, ACPI SCI is enabled during suspend/resume only,
-	 * update rtc irq in that case.
-	 */
-	if (cmos_use_acpi_alarm())
-		cmos_interrupt(0, (void *)cmos->rtc);
-	else {
-		/* Fix me: can we use cmos_interrupt() here as well? */
-		spin_lock_irqsave(&rtc_lock, flags);
-		if (cmos_rtc.suspend_ctrl)
-			rtc_control = CMOS_READ(RTC_CONTROL);
-		if (rtc_control & RTC_AIE) {
-			cmos_rtc.suspend_ctrl &= ~RTC_AIE;
-			CMOS_WRITE(rtc_control, RTC_CONTROL);
-			rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
-			rtc_update_irq(cmos->rtc, 1, rtc_intr);
-		}
-		spin_unlock_irqrestore(&rtc_lock, flags);
-	}
-
-	pm_wakeup_hard_event(dev);
-	acpi_clear_event(ACPI_EVENT_RTC);
-	acpi_disable_event(ACPI_EVENT_RTC, 0);
-	return ACPI_INTERRUPT_HANDLED;
-}
-
-static inline void rtc_wake_setup(struct device *dev)
-{
-	if (acpi_disabled)
-		return;
-
-	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
-	/*
-	 * After the RTC handler is installed, the Fixed_RTC event should
-	 * be disabled. Only when the RTC alarm is set will it be enabled.
-	 */
-	acpi_clear_event(ACPI_EVENT_RTC);
-	acpi_disable_event(ACPI_EVENT_RTC, 0);
-}
-
-static void rtc_wake_on(struct device *dev)
-{
-	acpi_clear_event(ACPI_EVENT_RTC);
-	acpi_enable_event(ACPI_EVENT_RTC, 0);
-}
-
-static void rtc_wake_off(struct device *dev)
-{
-	acpi_disable_event(ACPI_EVENT_RTC, 0);
-}
-
-#ifdef CONFIG_X86
-/* Enable use_acpi_alarm mode for Intel platforms no earlier than 2015 */
-static void use_acpi_alarm_quirks(void)
-{
-	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
-		return;
-
-	if (!is_hpet_enabled())
-		return;
-
-	if (dmi_get_bios_year() < 2015)
-		return;
-
-	use_acpi_alarm = true;
-}
-#else
-static inline void use_acpi_alarm_quirks(void) { }
-#endif
-
-static void cmos_wake_setup(struct device *dev)
-{
-	if (acpi_disabled)
-		return;
-
-	use_acpi_alarm_quirks();
-
-	cmos_rtc.wake_on = rtc_wake_on;
-	cmos_rtc.wake_off = rtc_wake_off;
-
-	/* ACPI tables bug workaround. */
-	if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
-		dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
-			acpi_gbl_FADT.month_alarm);
-		acpi_gbl_FADT.month_alarm = 0;
-	}
-
-	cmos_rtc.day_alrm = acpi_gbl_FADT.day_alarm;
-	cmos_rtc.mon_alrm = acpi_gbl_FADT.month_alarm;
-	cmos_rtc.century = acpi_gbl_FADT.century;
-
-	if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
-		dev_info(dev, "RTC can wake from S4\n");
-
-	/* RTC always wakes from S1/S2/S3, and often S4/STD */
-	device_init_wakeup(dev, 1);
-}
-
-static void cmos_check_acpi_rtc_status(struct device *dev,
-				       unsigned char *rtc_control)
-{
-	struct cmos_rtc *cmos = dev_get_drvdata(dev);
-	acpi_event_status rtc_status;
-	acpi_status status;
-
-	if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
-		return;
-
-	status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
-	if (ACPI_FAILURE(status)) {
-		dev_err(dev, "Could not get RTC status\n");
-	} else if (rtc_status & ACPI_EVENT_FLAG_SET) {
-		unsigned char mask;
-		*rtc_control &= ~RTC_AIE;
-		CMOS_WRITE(*rtc_control, RTC_CONTROL);
-		mask = CMOS_READ(RTC_INTR_FLAGS);
-		rtc_update_irq(cmos->rtc, 1, mask);
-	}
-}
-
-#else
-
-static void cmos_wake_setup(struct device *dev)
-{
-}
-
-static void cmos_check_acpi_rtc_status(struct device *dev,
-				       unsigned char *rtc_control)
-{
-}
-
-static void rtc_wake_setup(struct device *dev)
-{
-}
-#endif
-
 #ifdef	CONFIG_PNP
 
 #include <linux/pnp.h>

Rafael J. Wysocki

author

2022-11-09 12:15 UTC #4 lore raw

PATCH v2 4/5 rtc: rtc-cmos: Rename ACPI-related functions

In reply to Rafael J. Wysocki

From: Rafael J. Wysocki <[email protected]>

The names of rtc_wake_setup() and cmos_wake_setup() don't indicate that these functions are ACPI-related, which is the case, and the former doesn't really reflect the role of the function.

Rename them to acpi_rtc_event_setup() and acpi_cmos_wake_setup(), respectively, to address this shortcoming.

No intentional functional impact.

Signed-off-by Rafael J. Wysocki <[email protected]>

---

v1 -> v2:
* Use acpi_cmos_wake_setup() as the new name instead of cmos_acpi_wake_setup() (Andy)

---
 drivers/rtc/rtc-cmos.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

drivers/rtc/rtc-cmos.c +6 -6

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
@@ -784,7 +784,7 @@ static u32 rtc_handler(void *context)
 	return ACPI_INTERRUPT_HANDLED;
 }
 
-static void rtc_wake_setup(struct device *dev)
+static void acpi_rtc_event_setup(struct device *dev)
 {
 	if (acpi_disabled)
 		return;

@@ -828,7 +828,7 @@ static void use_acpi_alarm_quirks(void)
 static inline void use_acpi_alarm_quirks(void) { }
 #endif
 
-static void cmos_wake_setup(struct device *dev)
+static void acpi_cmos_wake_setup(struct device *dev)
 {
 	if (acpi_disabled)
 		return;

@@ -880,11 +880,11 @@ static void cmos_check_acpi_rtc_status(s
 
 #else /* !CONFIG_ACPI */
 
-static inline void rtc_wake_setup(struct device *dev)
+static inline void acpi_rtc_event_setup(struct device *dev)
 {
 }
 
-static inline void cmos_wake_setup(struct device *dev)
+static inline void acpi_cmos_wake_setup(struct device *dev)
 {
 }

@@ -986,7 +986,7 @@ cmos_do_probe(struct device *dev, struct
 			cmos_rtc.wake_off = info->wake_off;
 		}
 	} else {
-		cmos_wake_setup(dev);
+		acpi_cmos_wake_setup(dev);
 	}
 
 	if (cmos_rtc.day_alrm >= 128)

@@ -1091,7 +1091,7 @@ cmos_do_probe(struct device *dev, struct
 	 * the ACPI RTC fixed event.
 	 */
 	if (!info)
-		rtc_wake_setup(dev);
+		acpi_rtc_event_setup(dev);
 
 	dev_info(dev, "%s%s, %d bytes nvram%s\n",
 		 !is_valid_irq(rtc_irq) ? "no alarms" :

Rafael J. Wysocki

author

2022-11-09 12:15 UTC #5 lore raw

PATCH v2 5/5 rtc: rtc-cmos: Disable ACPI RTC event on removal

In reply to Rafael J. Wysocki

From: Rafael J. Wysocki <[email protected]>

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 <[email protected]>

---

v1 -> v2:
* Do not clear the driver data pointer (the driver core does that) (Andy)
* Adjust the code pattern in acpi_rtc_event_cleanup() (Andy)
* Drop inline from the full definition of acpi_rtc_event_cleanup()

---
 drivers/rtc/rtc-cmos.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

drivers/rtc/rtc-cmos.c +15 -0

Index: linux-pm/drivers/rtc/rtc-cmos.c
===================================================================
@@ -798,6 +798,14 @@ static void acpi_rtc_event_setup(struct
 	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(
 {
 }
 
+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
 			hpet_unregister_irq_handler(cmos_interrupt);
 	}
 
+	if (!dev_get_platdata(dev))
+		acpi_rtc_event_cleanup();
+
 	cmos->rtc = NULL;
 
 	ports = cmos->iomem;

Andy Shevchenko

Reviewed-by on the v2 series

2022-11-09 13:11 UTC #6 lore raw

In reply to Rafael J. Wysocki

Quoted 10 lines · Rafael J. Wysocki

Hi All,
This is a v2 of the series previously posted as
https://lore.kernel.org/linux-acpi/2276401.ElGaqSPkdT@kreacher/
The first three patches in the series have not changed since then (I have considered moving the last patch, which is a fix, to the front, but that turns out to be a bit cumbersome and not really worth the effort).

Quoted 8 lines

This series of patches does some assorted ACPI-related cleanups to the CMOS RTC driver:
- redundant static variable is dropped,
- code duplication is reduced,
- code is relocated so as to drop a few unnecessary forward declarations of functions,
- functions are renamed to avoid confusion,
and fixes up an issue in the driver removal path.

LGTM, FWIW,

Reviewed-by Andy Shevchenko <[email protected]>

Signature · 2 lines

With Best Regards,
Andy Shevchenko

Zhang Rui

Reviewed-by Tested-by on the v2 series

2022-11-10 12:00 UTC #7 lore raw

In reply to Rafael J. Wysocki

Quoted 12 lines · Rafael J. Wysocki

Hi All,
This is a v2 of the series previously posted as
https://lore.kernel.org/linux-acpi/2276401.ElGaqSPkdT@kreacher/
The first three patches in the series have not changed since then (I have
considered moving the last patch, which is a fix, to the front, but that turns
out to be a bit cumbersome and not really worth the effort).

Quoted 13 lines

This series of patches does some assorted ACPI-related cleanups to the CMOS RTC
driver:
- redundant static variable is dropped,
- code duplication is reduced,
- code is relocated so as to drop a few unnecessary forward declarations of
functions,
- functions are renamed to avoid confusion,
and fixes up an issue in the driver removal path.

Reviewed-by Zhang Rui <[email protected]>

And I have tested the patch series on a platform with both use_acpi_alarm parameter set and cleared, the ACPI RTC fixed event works as expected, for both runtime and suspend wakeups.

Tested-by Zhang Rui <[email protected]>

thanks,
rui

Alexandre Belloni

maintainer Applied

2022-11-15 20:08 UTC #8 lore raw

In reply to Rafael J. Wysocki

Quoted 9 lines · Rafael J. Wysocki

This is a v2 of the series previously posted as
https://lore.kernel.org/linux-acpi/2276401.ElGaqSPkdT@kreacher/
The first three patches in the series have not changed since then (I have considered moving the last patch, which is a fix, to the front, but that turns out to be a bit cumbersome and not really worth the effort).
[...]

Applied, thanks!

[1/5] rtc: rtc-cmos: Call cmos_wake_setup() from cmos_do_probe()

      commit: 508ccdfb86b21da37ad091003a4d4567709d5dfb
[2/5] rtc: rtc-cmos: Call rtc_wake_setup() from cmos_do_probe()
      commit: 375bbba09692fe4c5218eddee8e312dd733fa846
[3/5] rtc: rtc-cmos: Eliminate forward declarations of some functions
      commit: dca4d3b71c8a09a16951add656711fbd6f5bfbb0
[4/5] rtc: rtc-cmos: Rename ACPI-related functions
      commit: d13e9ad9f5146f066a5c5a1cc993d09e4fb21ead
[5/5] rtc: rtc-cmos: Disable ACPI RTC event on removal
      commit: 83ebb7b3036d151ee39a4a752018665648fc3bd4

Best regards,

Signature · 3 lines

Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com