4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier <marc.zyngier@xxxxxxx>
commit e8f241893dfbbebe2813c01eac54f263e6a5e59c upstream.
irq_modify_status starts by clearing the trigger settings from
irq_data before applying the new settings, but doesn't restore them,
leaving them to IRQ_TYPE_NONE.
That's pretty confusing to the potential request_irq() that could
follow. Instead, snapshot the settings before clearing them, and restore
them if the irq_modify_status() invocation was not changing the trigger.
Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Reported-and-tested-by: jeffy <jeffy.chen@xxxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jon Hunter <jonathanh@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170818095345.12378-1-marc.zyngier@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/irq/chip.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -895,13 +895,15 @@ EXPORT_SYMBOL_GPL(irq_set_chip_and_handl
void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
{
- unsigned long flags;
+ unsigned long flags, trigger, tmp;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return;
irq_settings_clr_and_set(desc, clr, set);
+ trigger = irqd_get_trigger_type(&desc->irq_data);
+
irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
if (irq_settings_has_no_balance_set(desc))
@@ -913,7 +915,11 @@ void irq_modify_status(unsigned int irq,
if (irq_settings_is_level(desc))
irqd_set(&desc->irq_data, IRQD_LEVEL);
- irqd_set(&desc->irq_data, irq_settings_get_trigger_mask(desc));
+ tmp = irq_settings_get_trigger_mask(desc);
+ if (tmp != IRQ_TYPE_NONE)
+ trigger = tmp;
+
+ irqd_set(&desc->irq_data, trigger);
irq_put_desc_unlock(desc, flags);
}