IRQCHIP: brcmstb-l2: don't clear wakeable interrupts at init time

Wakeable interrupts might be pending at boot/init time, because wakeup
interrupts might have triggered a resume from S5. So don't clear such
wakeups.

This means that any driver which requests a wakeable interrupt bit
should be prepared to handle an interrupt as soon as they call
request_irq(). (This is technically already the correct development
practice, but some drivers probably expect not to receive interrupts
until they have performed some I/O.)

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: f.fainelli@gmail.com
Cc: jaedon.shin@gmail.com
Cc: abrestic@chromium.org
Cc: tglx@linutronix.de
Cc: jason@lakedaemon.net
Cc: jogo@openwrt.org
Cc: arnd@arndb.de
Cc: computersforpeace@gmail.com
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8840/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/irqchip/irq-brcmstb-l2.c b/drivers/irqchip/irq-brcmstb-l2.c
index 313c2c64498a..d6bcc6be0777 100644
--- a/drivers/irqchip/irq-brcmstb-l2.c
+++ b/drivers/irqchip/irq-brcmstb-l2.c
@@ -136,7 +136,11 @@ int __init brcmstb_l2_intc_of_init(struct device_node *np,
 
         /* Disable all interrupts by default */
         writel(0xffffffff, data->base + CPU_MASK_SET);
-        writel(0xffffffff, data->base + CPU_CLEAR);
+
+        /* Wakeup interrupts may be retained from S5 (cold boot) */
+        data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
+        if (!data->can_wake)
+                writel(0xffffffff, data->base + CPU_CLEAR);
 
         data->parent_irq = irq_of_parse_and_map(np, 0);
         if (!data->parent_irq) {
@@ -188,8 +192,7 @@ int __init brcmstb_l2_intc_of_init(struct device_node *np,
         ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
         ct->chip.irq_resume = brcmstb_l2_intc_resume;
 
-        if (of_property_read_bool(np, "brcm,irq-can-wake")) {
-                data->can_wake = true;
+        if (data->can_wake) {
                 /* This IRQ chip can wake the system, set all child interrupts
                  * in wake_enabled mask
                  */