diff mbox

[V2,05/14] genirq: Look-up trigger type if not specified by caller

Message ID 1461150237-15580-6-git-send-email-jonathanh@nvidia.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jon Hunter April 20, 2016, 11:03 a.m. UTC
For some devices the IRQ trigger type for a device is read from
firmware, such as device-tree. The IRQ trigger type is typically read
when the mapping for IRQ is created, which is before the IRQ is
requested. Hence, the IRQ trigger type is programmed when mapping the
IRQ and not when requesting the IRQ.

Although this works for most cases, in order to support IRQ chips which
require runtime power management, which may not be accessible prior
to requesting the IRQ, it is desirable to look-up the IRQ trigger type
when it is requested. Therefore, if the IRQ trigger type is not
specified when __setup_irq() is called, look-up the saved IRQ trigger
type. This will allow us to defer the programming of the trigger type
from when the IRQ is mapped to when it is actually requested.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
 kernel/irq/manage.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox

Patch

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index cc1cc641d653..b2a93a37f772 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1117,6 +1117,13 @@  __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	new->irq = irq;
 
 	/*
+	 * If the trigger type is not specified by the caller,
+	 * then use the default for this interrupt.
+	 */
+	if (!(new->flags & IRQF_TRIGGER_MASK))
+		new->flags |= irqd_get_trigger_type(&desc->irq_data);
+
+	/*
 	 * Check whether the interrupt nests into another interrupt
 	 * thread.
 	 */