bcm27xx: add linux 5.4 support

Tested on bcm2710 (Raspberry Pi 3B).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0007-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch b/target/linux/bcm27xx/patches-5.4/950-0007-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch
new file mode 100644
index 0000000000..87aea08ba8
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0007-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch
@@ -0,0 +1,27 @@
+From 7e33284486a91fe400505003f49f50f496b906a7 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Fri, 4 Dec 2015 17:41:50 +0000
+Subject: [PATCH] irq-bcm2836: Prevent spurious interrupts, and trap
+ them early
+
+The old arch-specific IRQ macros included a dsb to ensure the
+write to clear the mailbox interrupt completed before returning
+from the interrupt. The BCM2836 irqchip driver needs the same
+precaution to avoid spurious interrupts.
+
+Spurious interrupts are still possible for other reasons,
+though, so trap them early.
+---
+ drivers/irqchip/irq-bcm2836.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/drivers/irqchip/irq-bcm2836.c
++++ b/drivers/irqchip/irq-bcm2836.c
+@@ -135,6 +135,7 @@ __exception_irq_entry bcm2836_arm_irqchi
+ 		u32 ipi = ffs(mbox_val) - 1;
+ 
+ 		writel(1 << ipi, mailbox0);
++		dsb(sy);
+ 		handle_IPI(ipi, regs);
+ #endif
+ 	} else if (stat) {