From: Julien Grall <julien.grall@linaro.org>
Date: Fri, 28 Jun 2013 11:25:57 +0000 (+0100)
Subject: xen/arm: gic_shutdown_irq must only disable the right IRQ
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~6682
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=751554bfc9dc0363fabf882f6e8855022590ec4d;p=xen.git

xen/arm: gic_shutdown_irq must only disable the right IRQ

When GICD_ICENABLERn is read, all the 1s bit represent enabled IRQs.
Currently gic_shutdown_irq:
    - read GICD_ICENABLER
    - set the corresping bit to 1
    - write back the new value
That means, Xen will disable more IRQs than necessary.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 177560e3d1..cafb68110a 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -117,12 +117,10 @@ static unsigned int gic_irq_startup(struct irq_desc *desc)
 
 static void gic_irq_shutdown(struct irq_desc *desc)
 {
-    uint32_t enabler;
     int irq = desc->irq;
 
     /* Disable routing */
-    enabler = GICD[GICD_ICENABLER + irq / 32];
-    GICD[GICD_ICENABLER + irq / 32] = enabler | (1u << (irq % 32));
+    GICD[GICD_ICENABLER + irq / 32] = (1u << (irq % 32));
 }
 
 static void gic_irq_enable(struct irq_desc *desc)