ARM: vexpress: Make cpuidle check for presence of SPC driver

The cpuidle code requires SPC hardware, so check for its presence
before initialising. This enables the cpuidle code to safely exist
in kernels run on hardware without SPC support.

Signed-off-by: Jon Medhurst <tixy@linaro.org>

diff --git a/arch/arm/mach-vexpress/cpuidle-tc2.c b/arch/arm/mach-vexpress/cpuidle-tc2.c
index de66243a7ef377aa6351fb7a01fcb5c367b1e06e..3b73d4a5dc5f83897c3818b7585d7fd4508a2d51 100644 (file)
--- a/arch/arm/mach-vexpress/cpuidle-tc2.c
+++ b/arch/arm/mach-vexpress/cpuidle-tc2.c
@@ -221,6 +221,11 @@ int __init tc2_idle_init(void)
        struct dentry *idle_debug, *file_debug;
        struct cpuidle_driver *drv = &tc2_idle_driver;
 
+       if (!vexpress_spc_check_loaded()) {
+               pr_info("TC2 CPUidle not registered because no SPC found\n");
+               return -ENODEV;
+       }
+
        drv->state_count = (sizeof(tc2_cpuidle_set) /
                                       sizeof(struct cpuidle_state));