diff mbox series

cpufreq: qcom-hw: Fix cpufreq_driver->get() for non-LMH systems

Message ID 20230202140005.1.I4b30aaa027c73372ec4068cc0f0dc665af8b938d@changeid
State New
Headers
Series cpufreq: qcom-hw: Fix cpufreq_driver->get() for non-LMH systems |

Commit Message

Doug Anderson Feb. 2, 2023, 10 p.m. UTC 
  On a sc7180-based Chromebook, when I go to
/sys/devices/system/cpu/cpu0/cpufreq I can see:

  cpuinfo_cur_freq:2995200
  cpuinfo_max_freq:1804800
  scaling_available_frequencies:300000 576000 ... 1708800 1804800
  scaling_cur_freq:1804800
  scaling_max_freq:1804800

As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
commit seems to assume that everyone is on the LMH bandwagon, but
sc7180 isn't.

Let's go back to the old code in the case where LMH isn't used.

Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 drivers/cpufreq/qcom-cpufreq-hw.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

Comments

Konrad Dybcio Feb. 2, 2023, 10:35 p.m. UTC | #1 
On 2.02.2023 23:00, Douglas Anderson wrote:
> On a sc7180-based Chromebook, when I go to
> /sys/devices/system/cpu/cpu0/cpufreq I can see:
> 
>   cpuinfo_cur_freq:2995200
>   cpuinfo_max_freq:1804800
>   scaling_available_frequencies:300000 576000 ... 1708800 1804800
>   scaling_cur_freq:1804800
>   scaling_max_freq:1804800
> 
> As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
> bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
> qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
> commit seems to assume that everyone is on the LMH bandwagon, but
> sc7180 isn't.
> 
> Let's go back to the old code in the case where LMH isn't used.
> 
> Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
Actually I hit the exact same issue when working on CPRh-aware
cpufreq with manual OSM programming.. LMh gets enabled by the firmware
on most recent platforms, but it's not the case for some old-timers.

I figured that adding a bool broken_lmh_freq in driver data would be
a good middleground between reverting that patch and ignoring the
issue, because it *does* matter what this function reports on LMh-
enabled platforms (yes, the subsystems are bluepilled between each
other and OSM/EPSS does not know the *real* throttled frequency),
but obviously we don't want to report 2.99Ghz otherwise..

I think 7280 had an issue where a SoC-specific compatible was not
introduced when the DT part was first merged, same goes for 6115.
6115 does have firmware-enabled LMh, not sure about 7280. In case
you wanted to go that route, I think it would be suitable to add
a blacklist of retroactively-broken platforms (match-by-machine-
compatible; don't scream at me bindings folks, I guess that's the
least messy solution) in addition to either matching the SoC-specific
compatible to epss_broken_lmh_driver_data.

Or we can forget about old DTs and just bind qcom,sc7180-cpufreq-hw
(and 7280, maybe? please check.) to this new driver data without
checking the machine compatible.



Konrad
> 
>  drivers/cpufreq/qcom-cpufreq-hw.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> index 9505a812d6a1..957cf6bb8c05 100644
> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -143,40 +143,42 @@ static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
>  	return lval * xo_rate;
>  }
>  
> -/* Get the current frequency of the CPU (after throttling) */
> -static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
> +/* Get the frequency requested by the cpufreq core for the CPU */
> +static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
>  {
>  	struct qcom_cpufreq_data *data;
> +	const struct qcom_cpufreq_soc_data *soc_data;
>  	struct cpufreq_policy *policy;
> +	unsigned int index;
>  
>  	policy = cpufreq_cpu_get_raw(cpu);
>  	if (!policy)
>  		return 0;
>  
>  	data = policy->driver_data;
> +	soc_data = qcom_cpufreq.soc_data;
>  
> -	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
> +	index = readl_relaxed(data->base + soc_data->reg_perf_state);
> +	index = min(index, LUT_MAX_ENTRIES - 1);
> +
> +	return policy->freq_table[index].frequency;
>  }
>  
> -/* Get the frequency requested by the cpufreq core for the CPU */
> -static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
> +static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
>  {
>  	struct qcom_cpufreq_data *data;
> -	const struct qcom_cpufreq_soc_data *soc_data;
>  	struct cpufreq_policy *policy;
> -	unsigned int index;
>  
>  	policy = cpufreq_cpu_get_raw(cpu);
>  	if (!policy)
>  		return 0;
>  
>  	data = policy->driver_data;
> -	soc_data = qcom_cpufreq.soc_data;
>  
> -	index = readl_relaxed(data->base + soc_data->reg_perf_state);
> -	index = min(index, LUT_MAX_ENTRIES - 1);
> +	if (data->throttle_irq >= 0)
> +		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
>  
> -	return policy->freq_table[index].frequency;
> +	return qcom_cpufreq_get_freq(cpu);
>  }
>  
>  static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
Konrad Dybcio Feb. 2, 2023, 10:45 p.m. UTC | #2 
On 2.02.2023 23:35, Konrad Dybcio wrote:
> 
> 
> On 2.02.2023 23:00, Douglas Anderson wrote:
>> On a sc7180-based Chromebook, when I go to
>> /sys/devices/system/cpu/cpu0/cpufreq I can see:
>>
>>   cpuinfo_cur_freq:2995200
>>   cpuinfo_max_freq:1804800
>>   scaling_available_frequencies:300000 576000 ... 1708800 1804800
>>   scaling_cur_freq:1804800
>>   scaling_max_freq:1804800
>>
>> As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
>> bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
>> qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
>> commit seems to assume that everyone is on the LMH bandwagon, but
>> sc7180 isn't.
>>
>> Let's go back to the old code in the case where LMH isn't used.
>>
>> Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")
>> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>> ---
> Actually I hit the exact same issue when working on CPRh-aware
> cpufreq with manual OSM programming.. LMh gets enabled by the firmware
> on most recent platforms, but it's not the case for some old-timers.
> 
Ignore this email, I can't read.

Konrad
> I figured that adding a bool broken_lmh_freq in driver data would be
> a good middleground between reverting that patch and ignoring the
> issue, because it *does* matter what this function reports on LMh-
> enabled platforms (yes, the subsystems are bluepilled between each
> other and OSM/EPSS does not know the *real* throttled frequency),
> but obviously we don't want to report 2.99Ghz otherwise..
> 
> I think 7280 had an issue where a SoC-specific compatible was not
> introduced when the DT part was first merged, same goes for 6115.
> 6115 does have firmware-enabled LMh, not sure about 7280. In case
> you wanted to go that route, I think it would be suitable to add
> a blacklist of retroactively-broken platforms (match-by-machine-
> compatible; don't scream at me bindings folks, I guess that's the
> least messy solution) in addition to either matching the SoC-specific
> compatible to epss_broken_lmh_driver_data.
> 
> Or we can forget about old DTs and just bind qcom,sc7180-cpufreq-hw
> (and 7280, maybe? please check.) to this new driver data without
> checking the machine compatible.
> 
> 
> 
> Konrad
>>
>>  drivers/cpufreq/qcom-cpufreq-hw.c | 24 +++++++++++++-----------
>>  1 file changed, 13 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
>> index 9505a812d6a1..957cf6bb8c05 100644
>> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
>> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
>> @@ -143,40 +143,42 @@ static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
>>  	return lval * xo_rate;
>>  }
>>  
>> -/* Get the current frequency of the CPU (after throttling) */
>> -static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
>> +/* Get the frequency requested by the cpufreq core for the CPU */
>> +static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
>>  {
>>  	struct qcom_cpufreq_data *data;
>> +	const struct qcom_cpufreq_soc_data *soc_data;
>>  	struct cpufreq_policy *policy;
>> +	unsigned int index;
>>  
>>  	policy = cpufreq_cpu_get_raw(cpu);
>>  	if (!policy)
>>  		return 0;
>>  
>>  	data = policy->driver_data;
>> +	soc_data = qcom_cpufreq.soc_data;
>>  
>> -	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
>> +	index = readl_relaxed(data->base + soc_data->reg_perf_state);
>> +	index = min(index, LUT_MAX_ENTRIES - 1);
>> +
>> +	return policy->freq_table[index].frequency;
>>  }
>>  
>> -/* Get the frequency requested by the cpufreq core for the CPU */
>> -static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
>> +static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
>>  {
>>  	struct qcom_cpufreq_data *data;
>> -	const struct qcom_cpufreq_soc_data *soc_data;
>>  	struct cpufreq_policy *policy;
>> -	unsigned int index;
>>  
>>  	policy = cpufreq_cpu_get_raw(cpu);
>>  	if (!policy)
>>  		return 0;
>>  
>>  	data = policy->driver_data;
>> -	soc_data = qcom_cpufreq.soc_data;
>>  
>> -	index = readl_relaxed(data->base + soc_data->reg_perf_state);
>> -	index = min(index, LUT_MAX_ENTRIES - 1);
>> +	if (data->throttle_irq >= 0)
>> +		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
>>  
>> -	return policy->freq_table[index].frequency;
>> +	return qcom_cpufreq_get_freq(cpu);
>>  }
>>  
>>  static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
Konrad Dybcio Feb. 2, 2023, 11:38 p.m. UTC | #3 
On 2.02.2023 23:00, Douglas Anderson wrote:
> On a sc7180-based Chromebook, when I go to
> /sys/devices/system/cpu/cpu0/cpufreq I can see:
> 
>   cpuinfo_cur_freq:2995200
>   cpuinfo_max_freq:1804800
>   scaling_available_frequencies:300000 576000 ... 1708800 1804800
>   scaling_cur_freq:1804800
>   scaling_max_freq:1804800
> 
> As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
> bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
> qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
> commit seems to assume that everyone is on the LMH bandwagon, but
> sc7180 isn't.
> 
> Let's go back to the old code in the case where LMH isn't used.
> 
> Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
I read it again, this time properly.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
> 
>  drivers/cpufreq/qcom-cpufreq-hw.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> index 9505a812d6a1..957cf6bb8c05 100644
> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -143,40 +143,42 @@ static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
>  	return lval * xo_rate;
>  }
>  
> -/* Get the current frequency of the CPU (after throttling) */
> -static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
> +/* Get the frequency requested by the cpufreq core for the CPU */
> +static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
>  {
>  	struct qcom_cpufreq_data *data;
> +	const struct qcom_cpufreq_soc_data *soc_data;
>  	struct cpufreq_policy *policy;
> +	unsigned int index;
>  
>  	policy = cpufreq_cpu_get_raw(cpu);
>  	if (!policy)
>  		return 0;
>  
>  	data = policy->driver_data;
> +	soc_data = qcom_cpufreq.soc_data;
>  
> -	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
> +	index = readl_relaxed(data->base + soc_data->reg_perf_state);
> +	index = min(index, LUT_MAX_ENTRIES - 1);
> +
> +	return policy->freq_table[index].frequency;
>  }
>  
> -/* Get the frequency requested by the cpufreq core for the CPU */
> -static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
> +static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
>  {
>  	struct qcom_cpufreq_data *data;
> -	const struct qcom_cpufreq_soc_data *soc_data;
>  	struct cpufreq_policy *policy;
> -	unsigned int index;
>  
>  	policy = cpufreq_cpu_get_raw(cpu);
>  	if (!policy)
>  		return 0;
>  
>  	data = policy->driver_data;
> -	soc_data = qcom_cpufreq.soc_data;
>  
> -	index = readl_relaxed(data->base + soc_data->reg_perf_state);
> -	index = min(index, LUT_MAX_ENTRIES - 1);
> +	if (data->throttle_irq >= 0)
> +		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
>  
> -	return policy->freq_table[index].frequency;
> +	return qcom_cpufreq_get_freq(cpu);
>  }
>  
>  static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
Manivannan Sadhasivam Feb. 4, 2023, 2:58 p.m. UTC | #4 
On Thu, Feb 02, 2023 at 02:00:23PM -0800, Douglas Anderson wrote:
> On a sc7180-based Chromebook, when I go to
> /sys/devices/system/cpu/cpu0/cpufreq I can see:
> 
>   cpuinfo_cur_freq:2995200
>   cpuinfo_max_freq:1804800
>   scaling_available_frequencies:300000 576000 ... 1708800 1804800
>   scaling_cur_freq:1804800
>   scaling_max_freq:1804800
> 
> As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
> bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
> qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
> commit seems to assume that everyone is on the LMH bandwagon, but
> sc7180 isn't.
> 

Ah, missed that part.

> Let's go back to the old code in the case where LMH isn't used.
> 

Thanks for fixing!

> Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

Thanks,
Mani

> ---
> 
>  drivers/cpufreq/qcom-cpufreq-hw.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> index 9505a812d6a1..957cf6bb8c05 100644
> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -143,40 +143,42 @@ static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
>  	return lval * xo_rate;
>  }
>  
> -/* Get the current frequency of the CPU (after throttling) */
> -static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
> +/* Get the frequency requested by the cpufreq core for the CPU */
> +static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
>  {
>  	struct qcom_cpufreq_data *data;
> +	const struct qcom_cpufreq_soc_data *soc_data;
>  	struct cpufreq_policy *policy;
> +	unsigned int index;
>  
>  	policy = cpufreq_cpu_get_raw(cpu);
>  	if (!policy)
>  		return 0;
>  
>  	data = policy->driver_data;
> +	soc_data = qcom_cpufreq.soc_data;
>  
> -	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
> +	index = readl_relaxed(data->base + soc_data->reg_perf_state);
> +	index = min(index, LUT_MAX_ENTRIES - 1);
> +
> +	return policy->freq_table[index].frequency;
>  }
>  
> -/* Get the frequency requested by the cpufreq core for the CPU */
> -static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
> +static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
>  {
>  	struct qcom_cpufreq_data *data;
> -	const struct qcom_cpufreq_soc_data *soc_data;
>  	struct cpufreq_policy *policy;
> -	unsigned int index;
>  
>  	policy = cpufreq_cpu_get_raw(cpu);
>  	if (!policy)
>  		return 0;
>  
>  	data = policy->driver_data;
> -	soc_data = qcom_cpufreq.soc_data;
>  
> -	index = readl_relaxed(data->base + soc_data->reg_perf_state);
> -	index = min(index, LUT_MAX_ENTRIES - 1);
> +	if (data->throttle_irq >= 0)
> +		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
>  
> -	return policy->freq_table[index].frequency;
> +	return qcom_cpufreq_get_freq(cpu);
>  }
>  
>  static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
> -- 
> 2.39.1.519.gcb327c4b5f-goog
>
Viresh Kumar Feb. 6, 2023, 4:10 a.m. UTC | #5 
On 02-02-23, 14:00, Douglas Anderson wrote:
> On a sc7180-based Chromebook, when I go to
> /sys/devices/system/cpu/cpu0/cpufreq I can see:
> 
>   cpuinfo_cur_freq:2995200
>   cpuinfo_max_freq:1804800
>   scaling_available_frequencies:300000 576000 ... 1708800 1804800
>   scaling_cur_freq:1804800
>   scaling_max_freq:1804800
> 
> As you can see the `cpuinfo_cur_freq` is bogus. It turns out that this
> bogus info started showing up as of commit 205f5e984d30 ("cpufreq:
> qcom-hw: Fix the frequency returned by cpufreq_driver->get()"). That
> commit seems to assume that everyone is on the LMH bandwagon, but
> sc7180 isn't.
> 
> Let's go back to the old code in the case where LMH isn't used.
> 
> Fixes: 205f5e984d30 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")

This is incorrect.

Fixes: c72cf0cb1d77 ("cpufreq: qcom-hw: Fix the frequency returned by cpufreq_driver->get()")

Applied. Thanks.
diff mbox series

Patch

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 9505a812d6a1..957cf6bb8c05 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -143,40 +143,42 @@  static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
 	return lval * xo_rate;
 }
 
-/* Get the current frequency of the CPU (after throttling) */
-static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
+/* Get the frequency requested by the cpufreq core for the CPU */
+static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
 {
 	struct qcom_cpufreq_data *data;
+	const struct qcom_cpufreq_soc_data *soc_data;
 	struct cpufreq_policy *policy;
+	unsigned int index;
 
 	policy = cpufreq_cpu_get_raw(cpu);
 	if (!policy)
 		return 0;
 
 	data = policy->driver_data;
+	soc_data = qcom_cpufreq.soc_data;
 
-	return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
+	index = readl_relaxed(data->base + soc_data->reg_perf_state);
+	index = min(index, LUT_MAX_ENTRIES - 1);
+
+	return policy->freq_table[index].frequency;
 }
 
-/* Get the frequency requested by the cpufreq core for the CPU */
-static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
+static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
 {
 	struct qcom_cpufreq_data *data;
-	const struct qcom_cpufreq_soc_data *soc_data;
 	struct cpufreq_policy *policy;
-	unsigned int index;
 
 	policy = cpufreq_cpu_get_raw(cpu);
 	if (!policy)
 		return 0;
 
 	data = policy->driver_data;
-	soc_data = qcom_cpufreq.soc_data;
 
-	index = readl_relaxed(data->base + soc_data->reg_perf_state);
-	index = min(index, LUT_MAX_ENTRIES - 1);
+	if (data->throttle_irq >= 0)
+		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
 
-	return policy->freq_table[index].frequency;
+	return qcom_cpufreq_get_freq(cpu);
 }
 
 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,