What's being done from CPUFREQ_INCOMPATIBLE, can also be done with
CPUFREQ_ADJUST. There is nothing special with CPUFREQ_INCOMPATIBLE
notifier.
Kill CPUFREQ_INCOMPATIBLE and fix its usage sites.
This also updates the numbering of notifier events to remove holes.
Signed-off-by: Viresh Kumar <[email protected]>
---
Documentation/cpu-freq/core.txt | 7 ++-----
drivers/acpi/processor_perflib.c | 2 +-
drivers/cpufreq/cpufreq.c | 4 ----
drivers/cpufreq/ppc_cbe_cpufreq_pmi.c | 4 ++--
drivers/video/fbdev/pxafb.c | 1 -
drivers/video/fbdev/sa1100fb.c | 1 -
include/linux/cpufreq.h | 9 ++++-----
7 files changed, 9 insertions(+), 19 deletions(-)
diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.txt
index 70933eadc308..ba78e7c2a069 100644
--- a/Documentation/cpu-freq/core.txt
+++ b/Documentation/cpu-freq/core.txt
@@ -55,16 +55,13 @@ transition notifiers.
----------------------------
These are notified when a new policy is intended to be set. Each
-CPUFreq policy notifier is called three times for a policy transition:
+CPUFreq policy notifier is called twice for a policy transition:
1.) During CPUFREQ_ADJUST all CPUFreq notifiers may change the limit if
they see a need for this - may it be thermal considerations or
hardware limitations.
-2.) During CPUFREQ_INCOMPATIBLE only changes may be done in order to avoid
- hardware failure.
-
-3.) And during CPUFREQ_NOTIFY all notifiers are informed of the new policy
+2.) And during CPUFREQ_NOTIFY all notifiers are informed of the new policy
- if two hardware drivers failed to agree on a new policy before this
stage, the incompatible hardware shall be shut down, and the user
informed of this.
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 47af702bb6a2..bb01dea39fdc 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -83,7 +83,7 @@ static int acpi_processor_ppc_notifier(struct notifier_block *nb,
if (ignore_ppc)
return 0;
- if (event != CPUFREQ_INCOMPATIBLE)
+ if (event != CPUFREQ_ADJUST)
return 0;
mutex_lock(&performance_mutex);
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 76a26609d96b..293f47b814bf 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2206,10 +2206,6 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy,
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_ADJUST, new_policy);
- /* adjust if necessary - hardware incompatibility*/
- blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
- CPUFREQ_INCOMPATIBLE, new_policy);
-
/*
* verify the cpu speed can be set within this limit, which might be
* different to the first one
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
index d29e8da396a0..7969f7690498 100644
--- a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
+++ b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
@@ -97,8 +97,8 @@ static int pmi_notifier(struct notifier_block *nb,
struct cpufreq_frequency_table *cbe_freqs;
u8 node;
- /* Should this really be called for CPUFREQ_ADJUST, CPUFREQ_INCOMPATIBLE
- * and CPUFREQ_NOTIFY policy events?)
+ /* Should this really be called for CPUFREQ_ADJUST and CPUFREQ_NOTIFY
+ * policy events?)
*/
if (event == CPUFREQ_START)
return 0;
diff --git a/drivers/video/fbdev/pxafb.c b/drivers/video/fbdev/pxafb.c
index 7245611ec963..94813af97f09 100644
--- a/drivers/video/fbdev/pxafb.c
+++ b/drivers/video/fbdev/pxafb.c
@@ -1668,7 +1668,6 @@ pxafb_freq_policy(struct notifier_block *nb, unsigned long val, void *data)
switch (val) {
case CPUFREQ_ADJUST:
- case CPUFREQ_INCOMPATIBLE:
pr_debug("min dma period: %d ps, "
"new clock %d kHz\n", pxafb_display_dma_period(var),
policy->max);
diff --git a/drivers/video/fbdev/sa1100fb.c b/drivers/video/fbdev/sa1100fb.c
index 89dd7e02197f..dcf774c15889 100644
--- a/drivers/video/fbdev/sa1100fb.c
+++ b/drivers/video/fbdev/sa1100fb.c
@@ -1042,7 +1042,6 @@ sa1100fb_freq_policy(struct notifier_block *nb, unsigned long val,
switch (val) {
case CPUFREQ_ADJUST:
- case CPUFREQ_INCOMPATIBLE:
dev_dbg(fbi->dev, "min dma period: %d ps, "
"new clock %d kHz\n", sa1100fb_min_dma_period(fbi),
policy->max);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index bde1e567b3a9..bedcc90c0757 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -369,11 +369,10 @@ static inline void cpufreq_resume(void) {}
/* Policy Notifiers */
#define CPUFREQ_ADJUST (0)
-#define CPUFREQ_INCOMPATIBLE (1)
-#define CPUFREQ_NOTIFY (2)
-#define CPUFREQ_START (3)
-#define CPUFREQ_CREATE_POLICY (4)
-#define CPUFREQ_REMOVE_POLICY (5)
+#define CPUFREQ_NOTIFY (1)
+#define CPUFREQ_START (2)
+#define CPUFREQ_CREATE_POLICY (3)
+#define CPUFREQ_REMOVE_POLICY (4)
#ifdef CONFIG_CPU_FREQ
int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
--
2.4.0
On 04/06/2016 02:21 PM, Rafael J. Wysocki wrote:
> On Wed, Apr 6, 2016 at 10:30 PM, Saravana Kannan <[email protected]> wrote:
>> On 09/09/2015 05:53 PM, Rafael J. Wysocki wrote:
>>>
>>> Hi,
>>>
>>> On Thu, Sep 10, 2015 at 2:39 AM, Viresh Kumar <[email protected]>
>>> wrote:
>>>>
>>>> On 10-09-15, 01:26, Rafael J. Wysocki wrote:
>>>>>
>>>>> On Monday, August 03, 2015 08:36:14 AM Viresh Kumar wrote:
>>>>>>
>>>>>> What's being done from CPUFREQ_INCOMPATIBLE, can also be done with
>>>>>> CPUFREQ_ADJUST. There is nothing special with CPUFREQ_INCOMPATIBLE
>>>>>> notifier.
>>>>>
>>>>>
>>>>> The above part of the changelog is a disaster to me. :-(
>>>>>
>>>>> It not only doesn't explain what really goes on, but it's actively
>>>>> confusing.
>>>>>
>>>>> What really happens is that the core sends CPUFREQ_INCOMPATIBLE
>>>>> notifications
>>>>> unconditionally right after sending the CPUFREQ_ADJUST ones, so the
>>>>> former is
>>>>> just redundant and it's more efficient to merge the two into one.
>>>>
>>>>
>>>> Undoubtedly this looks far better :)
>>>>
>>>> But, isn't this series already applied some time back ?
>>>
>>>
>>> Right, never mind. For some reason that patch was left in the "New"
>>> state.
>>>
>>> The code is OK.
>>
>>
>>
>> I guess I didn't notice this change when it was sent out.
>>
>> The comment that was deleted in this patch clearly states why the
>> INCOMPATIBLE notifier is needed. Some client might want to boost the CPU min
>> freq for performance or other reasons, but thermal might want to limit it.
>> So, by having thermal register for INCOMPATIBLE notifiers to enforce the
>> limits, we provide a way to guarantee it gets the final say.
>>
>> The real fix should have been to change drivers/thermal/cpu_cooling.c to use
>> CPUFREQ_INCOMPATIBLE instead of CPUFREQ_ADJUST.
>>
>> Is there something I'm missing? If not, can we please revert this patch?
>
> Well, nobody was using that event.
>
True, but that's more of a bug in drivers/thermal/cpu-cooling.c and
drivers/acpi/processor_thermal.c. We should revert this patch and fix
those drivers. Does that seem acceptable to you?
-Saravana
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
On Wed, Apr 6, 2016 at 11:29 PM, Saravana Kannan <[email protected]> wrote:
> On 04/06/2016 02:21 PM, Rafael J. Wysocki wrote:
>>
>> On Wed, Apr 6, 2016 at 10:30 PM, Saravana Kannan <[email protected]>
>> wrote:
>>>
>>> On 09/09/2015 05:53 PM, Rafael J. Wysocki wrote:
>>>>
[cut]
>>
>> Well, nobody was using that event.
>>
>
> True, but that's more of a bug in drivers/thermal/cpu-cooling.c and
> drivers/acpi/processor_thermal.c. We should revert this patch and fix those
> drivers. Does that seem acceptable to you?
I'd rather see a patch series adding the event back along with some
users. One user at least.
On 04/06/2016 02:45 PM, Rafael J. Wysocki wrote:
> On Wed, Apr 6, 2016 at 11:29 PM, Saravana Kannan <[email protected]> wrote:
>> On 04/06/2016 02:21 PM, Rafael J. Wysocki wrote:
>>>
>>> On Wed, Apr 6, 2016 at 10:30 PM, Saravana Kannan <[email protected]>
>>> wrote:
>>>>
>>>> On 09/09/2015 05:53 PM, Rafael J. Wysocki wrote:
>>>>>
>
> [cut]
>
>>>
>>> Well, nobody was using that event.
>>>
>>
>> True, but that's more of a bug in drivers/thermal/cpu-cooling.c and
>> drivers/acpi/processor_thermal.c. We should revert this patch and fix those
>> drivers. Does that seem acceptable to you?
>
> I'd rather see a patch series adding the event back along with some
> users. One user at least.
>
Ok, I'll make those two drivers use them and send it out. It's very
clearly a bug in those drivers.
-Saravana`
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project