[tip: irq/core] irqchip/versatile-fpga: Apply clear-mask earlier

[tip-bot2 for Sungbo Eo]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     6a214a28132f19ace3d835a6d8f6422ec80ad200
Gitweb:        https://git.kernel.org/tip/6a214a28132f19ace3d835a6d8f6422ec80ad200
Author:        Sungbo Eo <mans0n@xxxxxxxxxx>
AuthorDate:    Sat, 21 Mar 2020 22:38:42 +09:00
Committer:     Marc Zyngier <maz@xxxxxxxxxx>
CommitterDate: Sun, 22 Mar 2020 11:52:16 

irqchip/versatile-fpga: Apply clear-mask earlier

Clear its own IRQs before the parent IRQ get enabled, so that the
remaining IRQs do not accidentally interrupt the parent IRQ controller.

This patch also fixes a reboot bug on OX820 SoC, where the remaining
rps-timer IRQ raises a GIC interrupt that is left pending. After that,
the rps-timer IRQ is cleared during driver initialization, and there's
no IRQ left in rps-irq when local_irq_enable() is called, which evokes
an error message "unexpected IRQ trap".

Fixes: bdd272cbb97a ("irqchip: versatile FPGA: support cascaded interrupts from DT")
Signed-off-by: Sungbo Eo <mans0n@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20200321133842.2408823-1-mans0n@xxxxxxxxxx
---
 drivers/irqchip/irq-versatile-fpga.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-versatile-fpga.c b/drivers/irqchip/irq-versatile-fpga.c
index 70e2cff..f138673 100644
--- a/drivers/irqchip/irq-versatile-fpga.c
+++ b/drivers/irqchip/irq-versatile-fpga.c
@@ -212,6 +212,9 @@ int __init fpga_irq_of_init(struct device_node *node,
 	if (of_property_read_u32(node, "valid-mask", &valid_mask))
 		valid_mask = 0;
 
+	writel(clear_mask, base + IRQ_ENABLE_CLEAR);
+	writel(clear_mask, base + FIQ_ENABLE_CLEAR);
+
 	/* Some chips are cascaded from a parent IRQ */
 	parent_irq = irq_of_parse_and_map(node, 0);
 	if (!parent_irq) {
@@ -221,9 +224,6 @@ int __init fpga_irq_of_init(struct device_node *node,
 
 	fpga_irq_init(base, node->name, 0, parent_irq, valid_mask, node);
 
-	writel(clear_mask, base + IRQ_ENABLE_CLEAR);
-	writel(clear_mask, base + FIQ_ENABLE_CLEAR);
-
 	/*
 	 * On Versatile AB/PB, some secondary interrupts have a direct
 	 * pass-thru to the primary controller for IRQs 20 and 22-31 which need