diff mbox

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

Message ID CAMQu2gyooQ4x=ZGDZFg5BuBaEkgQx2kTAvtiGLEjXwOYvF_wMQ@mail.gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Santosh Shilimkar Aug. 8, 2012, 11:30 a.m. UTC
On Wed, Aug 8, 2012 at 4:24 PM, Rajendra Nayak <rnayak@ti.com> wrote:
>
> 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 <rnayak@ti.com>
> Cc: <linux-pm@vger.kernel.org>
> ---
>  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.

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Comments

Kevin Hilman Aug. 8, 2012, 5:28 p.m. UTC | #1
"Shilimkar, Santosh" <santosh.shilimkar@ti.com> writes:

> On Wed, Aug 8, 2012 at 4:24 PM, Rajendra Nayak <rnayak@ti.com> wrote:
>>
>> 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 <rnayak@ti.com>
>> Cc: <linux-pm@vger.kernel.org>
>> ---
>>  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)

I think you meant 'if (!freq_table)' ?

Kevin

>                 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;
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pm" in
> the body of a message to majordomo@vger.kernel.org
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Santosh Shilimkar Aug. 9, 2012, 5:27 a.m. UTC | #2
On Wed, Aug 8, 2012 at 10:58 PM, Kevin Hilman <khilman@ti.com> wrote:
>
> "Shilimkar, Santosh" <santosh.shilimkar@ti.com> writes:
>
> > On Wed, Aug 8, 2012 at 4:24 PM, Rajendra Nayak <rnayak@ti.com> wrote:
> >>
> >> 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 <rnayak@ti.com>
> >> Cc: <linux-pm@vger.kernel.org>
> >> ---
> >>  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)
>
> I think you meant 'if (!freq_table)' ?
>
Right.

regards
Santosh
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diff mbox

Patch

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;