[PATCH] cpufreq: Stop BUGing the system

From: Nishanth Menon
Date: Wed Dec 17 2014 - 10:52:43 EST


CPUFRreq subsystem is not a system catastrophic failure point.
Failures in these cases DONOT need complete system shutdown with BUG.
just refuse to let cpufreq function should be good enough.

Signed-off-by: Nishanth Menon <nm@xxxxxx>
---
drivers/cpufreq/cpufreq.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index a09a29c..a5aa2fa 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -281,7 +281,10 @@ static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
struct cpufreq_freqs *freqs, unsigned int state)
{
- BUG_ON(irqs_disabled());
+ if (irqs_disabled()) {
+ WARN(1, "IRQs disabled!\n");
+ return;
+ }

if (cpufreq_disabled())
return;
@@ -1253,9 +1256,12 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
/*
* Reaching here after boot in a few seconds may not
* mean that system will remain stable at "unknown"
- * frequency for longer duration. Hence, a BUG_ON().
+ * frequency for longer duration. Hence, a WARN().
*/
- BUG_ON(ret);
+ if (ret) {
+ WARN(1, "SYSTEM operating at invalid freq %u", policy->cur);
+ goto err_out_unregister;
+ }
pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
__func__, policy->cpu, policy->cur);
}
@@ -2556,7 +2562,10 @@ static int __init cpufreq_core_init(void)
return -ENODEV;

cpufreq_global_kobject = kobject_create();
- BUG_ON(!cpufreq_global_kobject);
+ if (!cpufreq_global_kobject) {
+ WARN(1, "No memory for cpufreq_global_kobject\n");
+ return -ENOMEM;
+ }

return 0;
}
--
1.7.9.5

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