From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: [PATCH V2 01/14] irqchip/gic: Don't unnecessarily write the IRQ configuration Date: Wed, 20 Apr 2016 12:03:44 +0100 Message-ID: <1461150237-15580-2-git-send-email-jonathanh@nvidia.com> References: <1461150237-15580-1-git-send-email-jonathanh@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1461150237-15580-1-git-send-email-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thomas Gleixner , Jason Cooper , Marc Zyngier , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Stephen Warren , Thierry Reding Cc: Kevin Hilman , Geert Uytterhoeven , Grygorii Strashko , Lars-Peter Clausen , Linus Walleij , linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jon Hunter List-Id: devicetree@vger.kernel.org If the interrupt configuration matches the current configuration, then don't bother writing the configuration again. Signed-off-by: Jon Hunter Acked-by: Marc Zyngier --- drivers/irqchip/irq-gic-common.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) 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) -- 2.1.4