1 files changed, 43 insertions, 0 deletions
diff --git a/debian/patches-rt/0056-irq_poll-Use-raise_softirq_irqoff-in-cpu_dead-notifi.patch b/debian/patches-rt/0056-irq_poll-Use-raise_softirq_irqoff-in-cpu_dead-notifi.patch
new file mode 100644
index 000000000..5bb35a340
--- /dev/null
+++ b/debian/patches-rt/0056-irq_poll-Use-raise_softirq_irqoff-in-cpu_dead-notifi.patch
@@ -0,0 +1,43 @@
+From ca7f829af53a908e0c480142361350e16d5da247 Mon Sep 17 00:00:00 2001
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Thu, 2 Apr 2020 21:16:30 +0200
+Subject: [PATCH 056/158] irq_poll: Use raise_softirq_irqoff() in cpu_dead
+ notifier
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.15/older/patches-5.15.10-rt24.tar.xz
+
+__raise_softirq_irqoff() adds a bit to the pending sofirq mask and this
+is it. The softirq won't be handled in a deterministic way but randomly
+when an interrupt fires and handles softirq in its irq_exit() routine or
+if something randomly checks and handles pending softirqs in the call
+chain before the CPU goes idle.
+
+Add a local_bh_disable/enable() around the IRQ-off section which will
+handle pending softirqs.
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Link: https://lkml.kernel.org/r/20210930103754.2128949-1-bigeasy@linutronix.de
+---
+ lib/irq_poll.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/lib/irq_poll.c b/lib/irq_poll.c
+index 2f17b488d58e..2b9f797642f6 100644
+--- a/lib/irq_poll.c
++++ b/lib/irq_poll.c
+@@ -191,11 +191,13 @@ static int irq_poll_cpu_dead(unsigned int cpu)
+ 	 * If a CPU goes away, splice its entries to the current CPU
+ 	 * and trigger a run of the softirq
+ 	 */
++	local_bh_disable();
+ 	local_irq_disable();
+ 	list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
+ 			 this_cpu_ptr(&blk_cpu_iopoll));
+ 	__raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+ 	local_irq_enable();
++	local_bh_enable();
+ 
+ 	return 0;
+ }
+-- 
+2.33.1
+