[PATCH 1/2] cpufreq: OMAP: Handle missing frequency table on SMP systems

On Wed, Aug 8, 2012 at 4:24 PM, Rajendra Nayak [off-list ref] wrote:

quoted

On OMAP4, if the first CPU fails to get a valid frequency table (this
could happen if the platform does not register any OPP table), the
subsequent CPU instances end up dealing with a NULL freq_table and
crash. Add a check for a NULL freq_table to help error the rest
of the CPU instances out.

Signed-off-by: Rajendra Nayak <redacted>
Cc: <redacted>
---
 drivers/cpufreq/omap-cpufreq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/omap-cpufreq.c

b/drivers/cpufreq/omap-cpufreq.c
index 17fa04d..0ee824c 100644

--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c

@@ -221,7 +221,7 @@ static int __cpuinit omap_cpu_init(struct

cpufreq_policy *policy)
        if (atomic_inc_return(&freq_table_users) == 1)
                result = opp_init_cpufreq_table(mpu_dev, &freq_table);

-       if (result) {
+       if (result || !freq_table) {
                dev_err(mpu_dev, "%s: cpu%d: failed creating freq
table[%d]\n",
                                __func__, policy->cpu, result);
                goto fail_ck;

The freq_table use count seems to be buggy in that case.
Something like below should fix the issue.
Feel free to update your patch with below if you agree.

diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 17fa04d..fd97c3d 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c

@@ -218,7 +218,7 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *po

        policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);

-       if (atomic_inc_return(&freq_table_users) == 1)
+       if (freq_table)

                result = opp_init_cpufreq_table(mpu_dev, &freq_table);

        if (result) {

@@ -227,6 +227,7 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *po
                goto fail_ck;
        }

+       atomic_inc_return(&freq_table_users);
        result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
        if (result)
                goto fail_table;
--

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