FAILED: patch "[PATCH] irqchip/stm32mp-exti: Fix the unit of the hwspinlock timeout" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-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 <stable@vger.kernel.org>.

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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x d31fbbade43f880b7e59e2b3a72722fe2725d93f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090814-trapper-singer-17bb@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From d31fbbade43f880b7e59e2b3a72722fe2725d93f Mon Sep 17 00:00:00 2001
From: Ju Nan <junan76@163.com>
Date: Fri, 21 Aug 2026 10:47:57 +0800
Subject: [PATCH] irqchip/stm32mp-exti: Fix the unit of the hwspinlock timeout

HWSPNLCK_TIMEOUT is passed to hwspin_lock_timeout_in_atomic(), whose
timeout argument is in milliseconds, not microseconds:

  atomic_delay += HWSPINLOCK_RETRY_DELAY_US;
  if (atomic_delay > to * 1000)
          return -ETIMEDOUT;

So stm32mp_exti_set_type() asks for a 1 second timeout where the comment
next to the macro says it wants 1 millisecond. The semaphore is polled
with udelay() from a section that holds chip_data->rlock, a
raw_spinlock_t, so preemption stays disabled for the whole wait on every
configuration, PREEMPT_RT included.

The hwspinlock core documents this explicitly:

  If the mode is HWLOCK_IN_ATOMIC (called from an atomic context) the
  timeout is handled with busy-waiting delays, hence shall not exceed
  few msecs.

Fixes: 5257169ade8c ("irqchip/stm32-exti: Use the hwspin_lock_timeout_in_atomic() API")
Signed-off-by: Ju Nan <junan76@163.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Radu Rendec <radu@rendec.net>
Reviewed-by: Antonio Borneo <antonio.borneo@foss.st.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260821024756.24927-2-junan76@163.com

diff --git a/drivers/irqchip/irq-stm32mp-exti.c b/drivers/irqchip/irq-stm32mp-exti.c
index bf3a2def69ca..a19e91fbd010 100644
--- a/drivers/irqchip/irq-stm32mp-exti.c
+++ b/drivers/irqchip/irq-stm32mp-exti.c
@@ -22,7 +22,7 @@
 
 #define IRQS_PER_BANK			32
 
-#define HWSPNLCK_TIMEOUT		1000 /* usec */
+#define HWSPNLCK_TIMEOUT_MS		1
 
 #define EXTI_EnCIDCFGR(n)		(0x180 + (n) * 4)
 #define EXTI_HWCFGR1			0x3f0
@@ -376,7 +376,7 @@ static int stm32mp_exti_set_type(struct irq_data *d, unsigned int type)
 	raw_spin_lock(&chip_data->rlock);
 
 	if (hwlock) {
-		err = hwspin_lock_timeout_in_atomic(hwlock, HWSPNLCK_TIMEOUT);
+		err = hwspin_lock_timeout_in_atomic(hwlock, HWSPNLCK_TIMEOUT_MS);
 		if (err) {
 			pr_err("%s can't get hwspinlock (%d)\n", __func__, err);
 			goto unlock;