Message-ID: <a536b3ba83d70d7f559597adcfdcf679@mail.piie.net>
Date:	Sun, 03 Jul 2016 09:03:45 +0000
From:	"Peter Feuerer" <peter@...e.net>
To:	"Darren Hart" <dvhart@...radead.org>,
	"Eduardo Valentin" <edubezval@...il.com>
Cc:	"Rui Zhang" <rui.zhang@...el.com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	"Len Brown" <lenb@...nel.org>, linux-acpi@...r.kernel.org,
	"Chun-Yi" <jlee@...e.com>, "Keerthy" <j-keerthy@...com>,
	linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org,
	platform-driver-x86@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCHv4 1/1] thermal: core: call
 thermal_zone_device_update() after mode update

Hi,

23. Juni 2016 06:52 Uhr, "Darren Hart" <dvhart@...radead.org> schrieb:
> On Wed, Jun 22, 2016 at 08:03:18AM -0700, Eduardo Valentin wrote:
> 
>> Because several drivers do the following pattern:
>> .set_mode()
>> ...
>> local_data->mode = new_mode;
>> thermal_zone_device_update(tz);
>> 
>> makes sense to simply do the thermal_zone_device_update()
>> in thermal core, after setting the new mode.
>> 
>> Also, this patch also remove deadlocks on drivers that
>> call thermal_zone_device_update() on .set_mode(),
>> as .set_mode() is now called always with tz->lock held.
>> 
>> Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
>> Cc: Len Brown <lenb@...nel.org>
>> Cc: linux-acpi@...r.kernel.org
>> Cc: "Lee, Chun-Yi" <jlee@...e.com>
>> Cc: Darren Hart <dvhart@...radead.org>
>> Cc: Zhang Rui <rui.zhang@...el.com>
>> Cc: Keerthy <j-keerthy@...com>
>> Cc: linux-kernel@...r.kernel.org
>> Cc: linux-omap@...r.kernel.org
>> Cc: platform-driver-x86@...r.kernel.org
>> Cc: linux-pm@...r.kernel.org
>> Signed-off-by: Eduardo Valentin <edubezval@...il.com>
> 
> +Peter Feuerer <peter@...e.net>
> 
> Peter, any concerns regarding the acerhdf driver?

Yes, please see below.



>> ---
>> Hello,
>> 
>> V3->V4:
>> - ti-soc: Removed extra locking from TI SoC in set_mode
>> - ACPI: Kept the update on check as it is called on other places
>> 
>> BR,
>> 
>> Eduardo
>> 
>> drivers/acpi/thermal.c | 1 -
>> drivers/platform/x86/acerhdf.c | 1 -
>> drivers/thermal/imx_thermal.c | 1 -
>> drivers/thermal/of-thermal.c | 5 -----
>> drivers/thermal/thermal_sysfs.c | 1 +

This file does not exist in Linus git master branch.  Which git repo / branch do you base your changes on?  Or are there any patches I need to apply first?


>> drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 5 -----
>> 6 files changed, 1 insertion(+), 13 deletions(-)
>> 
>> diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
>> index 82707f9..03c3460 100644
>> --- a/drivers/acpi/thermal.c
>> +++ b/drivers/acpi/thermal.c
>> @@ -581,7 +581,6 @@ static int thermal_set_mode(struct thermal_zone_device *thermal,
>> ACPI_DEBUG_PRINT((ACPI_DB_INFO,
>> "%s kernel ACPI thermal control\n",
>> tz->tz_enabled ? "Enable" : "Disable"));
>> - acpi_thermal_check(tz);
>> }
>> return 0;
>> }
>> diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
>> index 460fa67..aee33ba 100644
>> --- a/drivers/platform/x86/acerhdf.c
>> +++ b/drivers/platform/x86/acerhdf.c
>> @@ -405,7 +405,6 @@ static inline void acerhdf_enable_kernelmode(void)
>> kernelmode = 1;
>> 
>> thz_dev->polling_delay = interval*1000;
>> - thermal_zone_device_update(thz_dev);

This call is used to inform the thermal zone about the changed polling_delay from 0 (polling disabled) to some user defined interval at runtime - not initialization time.
>From just reading your patch I don't understand, how this is intended to work afterwards.  - I'm clearly missing some further info / patches to give my ok.


>> pr_notice("kernel mode fan control ON\n");
>> }
>> 
>> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
>> index c5547bd..a413eb6 100644
>> --- a/drivers/thermal/imx_thermal.c
>> +++ b/drivers/thermal/imx_thermal.c
>> @@ -246,7 +246,6 @@ static int imx_set_mode(struct thermal_zone_device *tz,
>> }
>> 
>> data->mode = mode;
>> - thermal_zone_device_update(tz);
>> 
>> return 0;
>> }
>> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
>> index b8e509c..95c47da 100644
>> --- a/drivers/thermal/of-thermal.c
>> +++ b/drivers/thermal/of-thermal.c
>> @@ -282,17 +282,12 @@ static int of_thermal_set_mode(struct thermal_zone_device *tz,
>> {
>> struct __thermal_zone *data = tz->devdata;
>> 
>> - mutex_lock(&tz->lock);
>> -
>> if (mode == THERMAL_DEVICE_ENABLED)
>> tz->polling_delay = data->polling_delay;
>> else
>> tz->polling_delay = 0;
>> 
>> - mutex_unlock(&tz->lock);
>> -
>> data->mode = mode;
>> - thermal_zone_device_update(tz);
>> 
>> return 0;
>> }
>> diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
>> index 743df50..3d0dc30 100644
>> --- a/drivers/thermal/thermal_sysfs.c
>> +++ b/drivers/thermal/thermal_sysfs.c
>> @@ -100,6 +100,7 @@ mode_store(struct device *dev, struct device_attribute *attr,
>> mutex_lock(&tz->lock);
>> result = tz->ops->set_mode(tz, mode);
>> mutex_unlock(&tz->lock);
>> + thermal_zone_device_update(tz);
>> 
>> if (result)
>> return result;
>> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> index 15c0a9a..5dce053 100644
>> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> @@ -193,19 +193,14 @@ static int ti_thermal_set_mode(struct thermal_zone_device *thermal,
>> return 0;
>> }
>> 
>> - mutex_lock(&data->ti_thermal->lock);
>> -
>> if (mode == THERMAL_DEVICE_ENABLED)
>> data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
>> else
>> data->ti_thermal->polling_delay = 0;
>> 
>> - mutex_unlock(&data->ti_thermal->lock);
>> -
>> data->mode = mode;
>> ti_bandgap_write_update_interval(bgp, data->sensor_id,
>> data->ti_thermal->polling_delay);
>> - thermal_zone_device_update(data->ti_thermal);
>> dev_dbg(&thermal->device, "thermal polling set for duration=%d msec\n",
>> data->ti_thermal->polling_delay);
>> 
>> --
>> 2.1.4

-- 
--peter;

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