This is a note to let you know that I've just added the patch titled
rtc: max77686: Do not enforce (incorrect) interrupt trigger type
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rtc-max77686-do-not-enforce-incorrect-interrupt-trig.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0aa6815396629162c2a783f4ff4f994745662e00
Author: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Date: Wed May 26 13:20:34 2021 -0400
rtc: max77686: Do not enforce (incorrect) interrupt trigger type
[ Upstream commit 742b0d7e15c333303daad4856de0764f4bc83601 ]
Interrupt line can be configured on different hardware in different way,
even inverted. Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.
The Maxim 77686 datasheet describes the interrupt line as active low
with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.
The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races. With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.
Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210526172036.183223-6-krzysztof.kozlowski@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
index 182fdd00e290..ecd61573dd31 100644
--- a/drivers/rtc/rtc-max77686.c
+++ b/drivers/rtc/rtc-max77686.c
@@ -718,8 +718,8 @@ static int max77686_init_rtc_regmap(struct max77686_rtc_info *info)
add_rtc_irq:
ret = regmap_add_irq_chip(info->rtc_regmap, info->rtc_irq,
- IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
- IRQF_SHARED, 0, info->drv_data->rtc_irq_chip,
+ IRQF_ONESHOT | IRQF_SHARED,
+ 0, info->drv_data->rtc_irq_chip,
&info->rtc_irq_data);
if (ret < 0) {
dev_err(info->dev, "Failed to add RTC irq chip: %d\n", ret);
