--- /dev/null
+From 00a39d8652ff9088de07a6fe6e9e1893452fe0dd Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Mateusz=20Jo=C5=84czyk?= <mat.jonczyk@o2.pl>
+Date: Sat, 7 Jun 2025 23:06:08 +0200
+Subject: rtc: cmos: use spin_lock_irqsave in cmos_interrupt
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Mateusz Jończyk <mat.jonczyk@o2.pl>
+
+commit 00a39d8652ff9088de07a6fe6e9e1893452fe0dd upstream.
+
+cmos_interrupt() can be called in a non-interrupt context, such as in
+an ACPI event handler (which runs in an interrupt thread). Therefore,
+usage of spin_lock(&rtc_lock) is insecure. Use spin_lock_irqsave() /
+spin_unlock_irqrestore() instead.
+
+Before a misguided
+commit 6950d046eb6e ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
+the cmos_interrupt() function used spin_lock_irqsave(). That commit
+changed it to spin_lock() and broke locking, which was partially fixed in
+commit 13be2efc390a ("rtc: cmos: Disable irq around direct invocation of cmos_interrupt()")
+
+That second commit did not take account of the ACPI fixed event handler
+pathway, however. It introduced local_irq_disable() workarounds in
+cmos_check_wkalrm(), which can cause problems on PREEMPT_RT kernels
+and are now unnecessary.
+
+Add an explicit comment so that this change will not be reverted by
+mistake.
+
+Cc: stable@vger.kernel.org
+Fixes: 6950d046eb6e ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
+Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
+Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
+Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com>
+Closes: https://lore.kernel.org/all/aDtJ92foPUYmGheF@debian.local/
+Link: https://lore.kernel.org/r/20250607210608.14835-1-mat.jonczyk@o2.pl
+Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/rtc/rtc-cmos.c | 10 ++++++----
+ 1 file changed, 6 insertions(+), 4 deletions(-)
+
+--- a/drivers/rtc/rtc-cmos.c
++++ b/drivers/rtc/rtc-cmos.c
+@@ -697,8 +697,12 @@ static irqreturn_t cmos_interrupt(int ir
+ {
+ u8 irqstat;
+ u8 rtc_control;
++ unsigned long flags;
+
+- spin_lock(&rtc_lock);
++ /* We cannot use spin_lock() here, as cmos_interrupt() is also called
++ * in a non-irq context.
++ */
++ spin_lock_irqsave(&rtc_lock, flags);
+
+ /* When the HPET interrupt handler calls us, the interrupt
+ * status is passed as arg1 instead of the irq number. But
+@@ -732,7 +736,7 @@ static irqreturn_t cmos_interrupt(int ir
+ hpet_mask_rtc_irq_bit(RTC_AIE);
+ CMOS_READ(RTC_INTR_FLAGS);
+ }
+- spin_unlock(&rtc_lock);
++ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ if (is_intr(irqstat)) {
+ rtc_update_irq(p, 1, irqstat);
+@@ -1300,9 +1304,7 @@ static void cmos_check_wkalrm(struct dev
+ * ACK the rtc irq here
+ */
+ if (t_now >= cmos->alarm_expires && cmos_use_acpi_alarm()) {
+- local_irq_disable();
+ cmos_interrupt(0, (void *)cmos->rtc);
+- local_irq_enable();
+ return;
+ }
+
--- /dev/null
+From 08d82d0cad51c2b1d454fe41ea1ff96ade676961 Mon Sep 17 00:00:00 2001
+From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
+Date: Thu, 29 May 2025 16:29:22 -0400
+Subject: rtc: pcf2127: add missing semicolon after statement
+
+From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
+
+commit 08d82d0cad51c2b1d454fe41ea1ff96ade676961 upstream.
+
+Replace comma with semicolon at the end of the statement when setting
+config.max_register.
+
+Fixes: fd28ceb4603f ("rtc: pcf2127: add variant-specific configuration structure")
+Cc: stable@vger.kernel.org
+Cc: Elena Popa <elena.popa@nxp.com>
+Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
+Link: https://lore.kernel.org/r/20250529202923.1552560-1-hugo@hugovil.com
+Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/rtc/rtc-pcf2127.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/rtc/rtc-pcf2127.c
++++ b/drivers/rtc/rtc-pcf2127.c
+@@ -1456,7 +1456,7 @@ static int pcf2127_spi_probe(struct spi_
+ variant = &pcf21xx_cfg[type];
+ }
+
+- config.max_register = variant->max_register,
++ config.max_register = variant->max_register;
+
+ regmap = devm_regmap_init_spi(spi, &config);
+ if (IS_ERR(regmap)) {
--- /dev/null
+From fa78e9b606a472495ef5b6b3d8b45c37f7727f9d Mon Sep 17 00:00:00 2001
+From: Elena Popa <elena.popa@nxp.com>
+Date: Fri, 30 May 2025 13:40:00 +0300
+Subject: rtc: pcf2127: fix SPI command byte for PCF2131
+
+From: Elena Popa <elena.popa@nxp.com>
+
+commit fa78e9b606a472495ef5b6b3d8b45c37f7727f9d upstream.
+
+PCF2131 was not responding to read/write operations using SPI. PCF2131
+has a different command byte definition, compared to PCF2127/29. Added
+the new command byte definition when PCF2131 is detected.
+
+Fixes: afc505bf9039 ("rtc: pcf2127: add support for PCF2131 RTC")
+Cc: stable@vger.kernel.org
+Signed-off-by: Elena Popa <elena.popa@nxp.com>
+Acked-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
+Link: https://lore.kernel.org/r/20250530104001.957977-1-elena.popa@nxp.com
+Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/rtc/rtc-pcf2127.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/drivers/rtc/rtc-pcf2127.c
++++ b/drivers/rtc/rtc-pcf2127.c
+@@ -1383,6 +1383,11 @@ static int pcf2127_i2c_probe(struct i2c_
+ variant = &pcf21xx_cfg[type];
+ }
+
++ if (variant->type == PCF2131) {
++ config.read_flag_mask = 0x0;
++ config.write_flag_mask = 0x0;
++ }
++
+ config.max_register = variant->max_register,
+
+ regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
projects / thirdparty / kernel / stable-queue.git / commitdiff
