FAILED: patch "[PATCH] gpio: mt7621: avoid corruption of shared interrupt trigger" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 1781172526d1092323af443fa03f00e6de560401
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026072039-grip-phony-0a5a@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1781172526d1092323af443fa03f00e6de560401 Mon Sep 17 00:00:00 2001
From: Sergio Paracuellos <[email protected]>
Date: Fri, 26 Jun 2026 08:01:09 +0200
Subject: [PATCH] gpio: mt7621: avoid corruption of shared interrupt trigger
state

The bank-shared fields like 'rising' and 'falling' are modified using non-atomic read-modify-write operations. Since every gpio chip instance represents an entire bank of 32 pins, if 'mediatek_gpio_irq_type()' is called concurrently for different IRQs on the same bank a possible overwrite of each other's configuration is possible. Thus, protect this state with 'gpio_generic_lock_irqsave' lock in the same way it is handled in irp_chip 'mediatek_gpio_irq_mask()' and 'mediatek_gpio_irq_unmask()' callbacks.

index a814885ccd5d..ceb99641baee 100644
@@ -187,6 +187,8 @@ mediatek_gpio_irq_type(struct irq_data *d, unsigned int type)
 	struct mtk_gc *rg = gpiochip_get_data(gc);
 	u32 mask = BIT(mt7621_gpio_hwirq_to_offset(d->hwirq, rg));
 
+	guard(gpio_generic_lock_irqsave)(&rg->chip);
+
 	if (type == IRQ_TYPE_PROBE) {
 		if ((rg->rising | rg->falling |
 		     rg->hlevel | rg->llevel) & mask)

From: Sergio Paracuellos <[email protected]>

[ Upstream commit 1781172526d1092323af443fa03f00e6de560401 ]

The bank-shared fields like 'rising' and 'falling' are modified using non-atomic read-modify-write operations. Since every gpio chip instance represents an entire bank of 32 pins, if 'mediatek_gpio_irq_type()' is called concurrently for different IRQs on the same bank a possible overwrite of each other's configuration is possible. Thus, protect this state with 'gpio_generic_lock_irqsave' lock in the same way it is handled in irp_chip 'mediatek_gpio_irq_mask()' and 'mediatek_gpio_irq_unmask()' callbacks.

---
 drivers/gpio/gpio-mt7621.c | 2 ++
 1 file changed, 2 insertions(+)

index c3658a597a80a0..bf08f6894ae063 100644
@@ -153,6 +153,8 @@ mediatek_gpio_irq_type(struct irq_data *d, unsigned int type)
 	int pin = d->hwirq;
 	u32 mask = BIT(pin);
 
+	guard(spinlock_irqsave)(&rg->lock);
+
 	if (type == IRQ_TYPE_PROBE) {
 		if ((rg->rising | rg->falling |
 		     rg->hlevel | rg->llevel) & mask)

2.53.0