diff mbox

[03/15] irqchip/gic: Don't unnecessarily write the IRQ configuration

Message ID 1458224359-32665-4-git-send-email-jonathanh@nvidia.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jon Hunter March 17, 2016, 2:19 p.m. UTC 
If the interrupt configuration matches the current configuration, then
don't bother writing the configuration again.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
 drivers/irqchip/irq-gic-common.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Comments

Marc Zyngier April 9, 2016, 10:50 a.m. UTC | #1 
On Thu, 17 Mar 2016 14:19:07 +0000
Jon Hunter <jonathanh@nvidia.com> wrote:

> If the interrupt configuration matches the current configuration, then
> don't bother writing the configuration again.
> 
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

	M.
diff mbox

Patch

diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c
index f174ce0ca361..ffff5a45f1e3 100644
--- a/drivers/irqchip/irq-gic-common.c
+++ b/drivers/irqchip/irq-gic-common.c
@@ -50,13 +50,17 @@  int gic_configure_irq(unsigned int irq, unsigned int type,
 	else if (type & IRQ_TYPE_EDGE_BOTH)
 		val |= confmask;
 
+	/* If the current configuration is the same, then we are done */
+	if (val == oldval)
+		return 0;
+
 	/*
 	 * Write back the new configuration, and possibly re-enable
-	 * the interrupt. If we tried to write a new configuration and failed,
+	 * the interrupt. If we fail to write a new configuration,
 	 * return an error.
 	 */
 	writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
-	if (readl_relaxed(base + GIC_DIST_CONFIG + confoff) != val && val != oldval)
+	if (readl_relaxed(base + GIC_DIST_CONFIG + confoff) != val)
 		ret = -EINVAL;
 
 	if (sync_access)