thermal: cpu_cooling: check for the readiness of cpufreq layer
Subsystems (5)
Eduardo Valentin
maintainerPATCH v2 1/1 thermal: cpu_cooling: check for the readiness of cpufreq layer
In this patch, the cpu_cooling code checks for the usability of cpufreq layer before proceeding with the CPU cooling device registration. The main reason is: CPU cooling device is not usable if cpufreq cannot switch frequencies.
Similar checks are spread in thermal drivers. Thus, the advantage now is to have the check in a single place: cpu cooling device registration. For this reason, this patch also updates the existing drivers that depend on CPU cooling to simply propagate the error code of the cpu cooling registration call. Therefore, in case cpufreq is not ready, the thermal drivers will still return -EPROBE_DEFER, in an attempt to try again when cpufreq layer gets ready.
--- drivers/thermal/cpu_cooling.c | 5 +++++ drivers/thermal/db8500_cpufreq_cooling.c | 5 ----- drivers/thermal/imx_thermal.c | 5 ----- drivers/thermal/samsung/exynos_thermal_common.c | 2 +- drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 6 ------ 5 files changed, 6 insertions(+), 17 deletions(-)
---
(I'm sorry VireshK, I am still using my normal practice) :-)
Changes from V1:
- As per Viresh K. suggestion's, the check for cpufreq layer readiness is now only a simple fetch for cpufreq table.
drivers/thermal/cpu_cooling.c +5 -0
@@ -440,6 +440,11 @@ __cpufreq_cooling_register(struct device_node *np,int ret =0 , i;struct cpufreq_policy policy; +if (!cpufreq_frequency_get_table (0 )) { +pr_err ("cpu_cooling: cpufreq layer not ready! Deferring.\n" ); +return ERR_PTR (-EPROBE_DEFER ); + } +/* Verify that all the clip cpus have same freq_min, freq_max limit */ for_each_cpu (i, clip_cpus) {/* continue if cpufreq policy not found and not return error */
drivers/thermal/db8500_cpufreq_cooling.c +0 -5
@@ -18,7 +18,6 @@*/ #include <linux/cpu_cooling.h> -#include <linux/cpufreq.h> #include <linux/err.h> #include <linux/module.h> #include <linux/of.h>
@@ -30,10 +29,6 @@ static int db8500_cpufreq_cooling_probe(struct platform_device *pdev)struct thermal_cooling_device *cdev;struct cpumask mask_val; -/* make sure cpufreq driver has been initialized */ -if (!cpufreq_frequency_get_table (0 )) -return -EPROBE_DEFER ; -cpumask_set_cpu (0 , &mask_val); cdev =cpufreq_cooling_register (&mask_val);
drivers/thermal/imx_thermal.c +0 -5
@@ -9,7 +9,6 @@#include <linux/clk.h> #include <linux/cpu_cooling.h> -#include <linux/cpufreq.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/init.h>
@@ -459,10 +458,6 @@ static int imx_thermal_probe(struct platform_device *pdev)int measure_freq;int ret; -if (!cpufreq_get_current_driver ()) { -dev_dbg (&pdev->dev,"no cpufreq driver!" ); -return -EPROBE_DEFER ; - } data =devm_kzalloc (&pdev->dev,sizeof (*data),GFP_KERNEL );if (!data)return -ENOMEM ;
drivers/thermal/samsung/exynos_thermal_common.c +1 -1
@@ -373,7 +373,7 @@ int exynos_register_thermal(struct thermal_sensor_conf *sensor_conf)if (IS_ERR (th_zone->cool_dev[th_zone->cool_dev_size])) {dev_err (sensor_conf->dev,"Failed to register cpufreq cooling device\n" ); - ret = -EINVAL ; + ret =PTR_ERR (th_zone->cool_dev[th_zone->cool_dev_size]); goto err_unregister; } th_zone->cool_dev_size++;
drivers/thermal/ti-soc-thermal/ti-thermal-common.c +0 -6
@@ -28,7 +28,6 @@#include <linux/kernel.h> #include <linux/workqueue.h> #include <linux/thermal.h> -#include <linux/cpufreq.h> #include <linux/cpumask.h> #include <linux/cpu_cooling.h> #include <linux/of.h>
@@ -407,11 +406,6 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)if (!data)return -EINVAL ; -if (!cpufreq_get_current_driver ()) { -dev_dbg (bgp->dev,"no cpufreq driver yet\n" ); -return -EPROBE_DEFER ; - } -/* Register cooling device */ data->cool_dev =cpufreq_cooling_register (cpu_present_mask);if (IS_ERR (data->cool_dev)) {
Signature · 1 line
2.1.3
Quoted 1 line · Eduardo Valentin
(I'm sorry VireshK, I am still using my normal practice) :-)
That's fine :)
drivers/thermal/cpu_cooling.c __cpufreq_cooling_register(struct device_node *np, · line 444
Quoted 10 lines
drivers/thermal/cpu_cooling.c +2
-0@@ -440,6 +440,11 @@ __cpufreq_cooling_register(struct device_node *np,int ret =0 , i;struct cpufreq_policy policy; +if (!cpufreq_frequency_get_table (0 )) { +pr_err ("cpu_cooling: cpufreq layer not ready! Deferring.\n" );
Throwing an error here doesn't look to be the right thing. Ultimately we will register the cooling dev when probed again after some time.
So, a pr_debug() suits more here.
Also, this breaks existing exynos thermal drivers as they don't handle -EPROBE_DEFER well right now.
I reached here, because one of my patches had something similar to what you wrote. Just for this file though, haven't updated any other drivers though.
Will be sending you my small patchset by end of day today, please see if they make any sense at all..
Quoted 21 lines · On Fri, 28 Nov 2014 13:35:49 +0530 Viresh Kumar <[email protected]> wrote:
Quoted 1 line · Eduardo Valentin
(I'm sorry VireshK, I am still using my normal practice) :-)
That's fine :)
drivers/thermal/cpu_cooling.c __cpufreq_cooling_register(struct device_node · line 445
Quoted 11 lines
(quoted diff) +0
-0
b/drivers/thermal/cpu_cooling.cindex 1ab0018..bed3fa2 100644drivers/thermal/cpu_cooling.c +2
-0@@ -440,6 +440,11 @@ __cpufreq_cooling_register(struct device_node *np, int ret = 0, i;struct cpufreq_policy policy; +if (!cpufreq_frequency_get_table (0 )) { + pr_err("cpu_cooling: cpufreq layer not ready! Deferring.\n");Throwing an error here doesn't look to be the right thing. Ultimately we will register the cooling dev when probed again after some time.
Quoted 4 lines
So, a
pr_debug()suits more here.Also, this breaks existing exynos thermal drivers as they don't handle -EPROBE_DEFER well right now.
Unfortunately Viresh is correct here. Current (before rework) Exynos TMU driver expects that cpu_cooling device will succeed.
Quoted 7 lines
I reached here, because one of my patches had something similar to what you wrote. Just for this file though, haven't updated any other drivers though.
Will be sending you my small patchset by end of day today, please see if they make any sense at all..
Best regards,
?ukasz Majewski
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Eduardo Valentin
maintainerHello Folks,
Quoted 24 lines · Lukasz Majewski
Quoted 21 lines · On Fri, 28 Nov 2014 13:35:49 +0530 Viresh Kumar <[email protected]> wrote:
Quoted 1 line · Eduardo Valentin
(I'm sorry VireshK, I am still using my normal practice) :-)
That's fine :)
drivers/thermal/cpu_cooling.c __cpufreq_cooling_register(struct device_node · line 445
Quoted 11 lines
(quoted diff) +0
-0
b/drivers/thermal/cpu_cooling.cindex 1ab0018..bed3fa2 100644drivers/thermal/cpu_cooling.c +2
-0@@ -440,6 +440,11 @@ __cpufreq_cooling_register(struct device_node *np, int ret = 0, i;struct cpufreq_policy policy; +if (!cpufreq_frequency_get_table (0 )) { + pr_err("cpu_cooling: cpufreq layer not ready! Deferring.\n");Throwing an error here doesn't look to be the right thing. Ultimately we will register the cooling dev when probed again after some time.
Quoted 2 lines
Quoted 2 lines
So, a
pr_debug()suits more here.
Yeah, I agree here.
Quoted 6 lines
Quoted 2 lines
Also, this breaks existing exynos thermal drivers as they don't handle -EPROBE_DEFER well right now.
Unfortunately Viresh is correct here. Current (before rework) Exynos TMU driver expects that
cpu_coolingdevice will succeed.
Well, I wouldn't say unfortunately, but fortunately! :-)
Ok. But I believe it is a matter of propagating the error code. As I included in this patch:
drivers/thermal/samsung/exynos_thermal_common.c +1 -1
@@ -373,7 +373,7 @@ int exynos_register_thermal(struct thermal_sensor_conf *sensor_conf)if (IS_ERR (th_zone->cool_dev[th_zone->cool_dev_size])) {dev_err (sensor_conf->dev,"Failed to register cpufreq cooling device\n" ); - ret = -EINVAL ; + ret =PTR_ERR (th_zone->cool_dev[th_zone->cool_dev_size]); goto err_unregister; } th_zone->cool_dev_size++;
Quoted 7 lines
Quoted 7 lines
I reached here, because one of my patches had something similar to what you wrote. Just for this file though, haven't updated any other drivers though.
Will be sending you my small patchset by end of day today, please see if they make any sense at all..
The version you sent (for exynos) is better because there is a check for not print error messages in case of deferring.
However, I would prefer, at least to what comes to deferring, to update the drivers altogether with the inclusion of the check in cpu cooling. This way the change in behavior is atomic, in terms of commit changes.
Viresh, if you don't mind, I will merge your patch 04/26 into this one.
Quoted 3 lines
Best regards,
?ukasz Majewski
BR, Eduardo Valentin
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Quoted 1 line · Eduardo Valentin
Well, I wouldn't say unfortunately, but fortunately! :-)
+1 :)
Quoted 5 lines
However, I would prefer, at least to what comes to deferring, to update the drivers altogether with the inclusion of the check in cpu cooling. This way the change in behavior is atomic, in terms of commit changes.
Viresh, if you don't mind, I will merge your patch 04/26 into this one.
Sure, go ahead.