* [PATCH] cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index()
@ 2016-07-21 21:23 Viresh Kumar
2016-07-21 21:37 ` Rafael J. Wysocki
0 siblings, 1 reply; 2+ messages in thread
From: Viresh Kumar @ 2016-07-21 21:23 UTC (permalink / raw)
To: Rafael Wysocki, Viresh Kumar
Cc: linaro-kernel, linux-pm, linux-kernel, steve.muckle, peterz,
mingo, vincent.guittot, morten.rasmussen, dietmar.eggemann,
Juri.Lelli, patrick.bellasi
The handlers provided by cpufreq core are sufficient for resolving the
frequency for drivers providing ->target_index(), as the core already
has the frequency table and so ->resolve_freq() isn't required for such
platforms.
This patch disallows drivers with ->target_index() callback to use the
->resolve_freq() callback.
Also, it fixes a potential kernel crash for drivers providing ->target()
but no ->resolve_freq().
Fixes: e3c062360870 ("cpufreq: add cpufreq_driver_resolve_freq()")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b696baeb249d..342bbee8d0e1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -507,12 +507,20 @@ unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
{
target_freq = clamp_val(target_freq, policy->min, policy->max);
policy->cached_target_freq = target_freq;
+
+ if (cpufreq_driver->target_index) {
+ int idx;
+
+ idx = cpufreq_frequency_table_target(policy, target_freq,
+ CPUFREQ_RELATION_L);
+ policy->cached_resolved_idx = idx;
+ return policy->freq_table[idx].frequency;
+ }
+
if (cpufreq_driver->resolve_freq)
return cpufreq_driver->resolve_freq(policy, target_freq);
- policy->cached_resolved_idx =
- cpufreq_frequency_table_target(policy, target_freq,
- CPUFREQ_RELATION_L);
- return policy->freq_table[policy->cached_resolved_idx].frequency;
+
+ return UINT_MAX;
}
/*********************************************************************
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index()
2016-07-21 21:23 [PATCH] cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index() Viresh Kumar
@ 2016-07-21 21:37 ` Rafael J. Wysocki
0 siblings, 0 replies; 2+ messages in thread
From: Rafael J. Wysocki @ 2016-07-21 21:37 UTC (permalink / raw)
To: Viresh Kumar
Cc: Rafael Wysocki, Lists linaro-kernel, Linux PM,
Linux Kernel Mailing List, Steve Muckle, Peter Zijlstra,
Ingo Molnar, Vincent Guittot, Morten Rasmussen, Dietmar Eggemann,
Juri Lelli, Patrick Bellasi
On Thu, Jul 21, 2016 at 11:23 PM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> The handlers provided by cpufreq core are sufficient for resolving the
> frequency for drivers providing ->target_index(), as the core already
> has the frequency table and so ->resolve_freq() isn't required for such
> platforms.
>
> This patch disallows drivers with ->target_index() callback to use the
> ->resolve_freq() callback.
>
> Also, it fixes a potential kernel crash for drivers providing ->target()
> but no ->resolve_freq().
>
> Fixes: e3c062360870 ("cpufreq: add cpufreq_driver_resolve_freq()")
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> drivers/cpufreq/cpufreq.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index b696baeb249d..342bbee8d0e1 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -507,12 +507,20 @@ unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
> {
> target_freq = clamp_val(target_freq, policy->min, policy->max);
> policy->cached_target_freq = target_freq;
> +
> + if (cpufreq_driver->target_index) {
> + int idx;
> +
> + idx = cpufreq_frequency_table_target(policy, target_freq,
> + CPUFREQ_RELATION_L);
> + policy->cached_resolved_idx = idx;
> + return policy->freq_table[idx].frequency;
> + }
> +
> if (cpufreq_driver->resolve_freq)
> return cpufreq_driver->resolve_freq(policy, target_freq);
> - policy->cached_resolved_idx =
> - cpufreq_frequency_table_target(policy, target_freq,
> - CPUFREQ_RELATION_L);
> - return policy->freq_table[policy->cached_resolved_idx].frequency;
> +
> + return UINT_MAX;
I think it should just return target_freq in this case or the UINT_MAX
will confuse things in schedutil.
Thanks,
Rafael
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2016-07-21 21:37 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-07-21 21:23 [PATCH] cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index() Viresh Kumar
2016-07-21 21:37 ` Rafael J. Wysocki
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.