ARM: exynos: Fix infinite loops on CPU powerup failure

Add timeout to infinite loops during the CPU powerup procedures. It
is better to report an error instead of busylooping for infinite time
in case of failure.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
index 72bc035bedbe2702b08a866f1bfc5973a48e9879..9a681b421ae119887dc8abf90de2cf889489b389 100644 (file)
--- a/arch/arm/mach-exynos/mcpm-exynos.c
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -75,14 +75,25 @@ static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
                 */
                if (cluster &&
                    cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) {
+                       unsigned int timeout = 16;
+
                        /*
                         * Before we reset the Little cores, we should wait
                         * the SPARE2 register is set to 1 because the init
                         * codes of the iROM will set the register after
                         * initialization.
                         */
-                       while (!pmu_raw_readl(S5P_PMU_SPARE2))
+                       while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
+                               timeout--;
                                udelay(10);
+                       }
+
+                       if (timeout == 0) {
+                               pr_err("cpu %u cluster %u powerup failed\n",
+                                      cpu, cluster);
+                               exynos_cpu_power_down(cpunr);
+                               return -ETIMEDOUT;
+                       }
 
                        pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
                                        EXYNOS_SWRESET);

diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index abcac616423319bf0634bce260a85c3fe9134b60..0cbbae8bf1f85ef4dcf4dc245c12760fdd0c4e6a 100644 (file)
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -214,13 +214,20 @@ static inline void __iomem *cpu_boot_reg(int cpu)
  */
 void exynos_core_restart(u32 core_id)
 {
+       unsigned int timeout = 16;
        u32 val;
 
        if (!of_machine_is_compatible("samsung,exynos3250"))
                return;
 
-       while (!pmu_raw_readl(S5P_PMU_SPARE2))
+       while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
+               timeout--;
                udelay(10);
+       }
+       if (timeout == 0) {
+               pr_err("cpu core %u restart failed\n", core_id);
+               return;
+       }
        udelay(10);
 
        val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));