Re: [V6,3/9] irqdomain: Don't set type when mapping an IRQ

From: jeffy
Date: Thu Aug 17 2017 - 10:42:34 EST


Hi Marc,

Thanks for your reply.

On 08/17/2017 09:34 PM, Marc Zyngier wrote:
On 17/08/17 13:46, jeffy wrote:
Hi guys,

I hit an problem when testing a level triggered irq with:

irq = platform_get_irq_byname(pdev, "wake");
...<-- irq trigger type is correct
irq_set_status_flags(irq, IRQ_NOAUTOEN);
...<-- irq trigger type become zero
request_threaded_irq(irq, ...)

the trigger type lost(irqd_get_trigger_type returns zero) after
irq_set_status_flags.


it looks like irq_set_status_flags would try to use
irq_settings_is_level to get level trigger type, which would get zero
since we removed set type here...could you help to check this, thanks :)

Hmm. That's quite unexpected. Can you please try this?

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index a3cc37c0c85e..3675c6004f2a 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1000,7 +1000,7 @@ EXPORT_SYMBOL_GPL(irq_set_chip_and_handler_name);

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)
@@ -1014,6 +1014,8 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)

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))
@@ -1025,7 +1027,11 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
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);
}

Basically, save the trigger info before clearing it. If the interrupt
has already been configured, use that. Otherwise restore the previous
trigger settings. But I'm slightly confused as to which field is used
for what...

Thanks:), this patch works well, so

Tested-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>


M.