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* [PATCH] PM / devfreq: Add debugfs support with devfreq_summary file
       [not found] <CGME20191226060101epcas1p11a225c00bb7ab2f6b7895b4cb00b9871@epcas1p1.samsung.com>
@ 2019-12-26  6:07 ` Chanwoo Choi
  2019-12-30  3:26   ` Nathan Chancellor
  0 siblings, 1 reply; 3+ messages in thread
From: Chanwoo Choi @ 2019-12-26  6:07 UTC (permalink / raw)
  To: linux-pm, linux-kernel; +Cc: cw00.choi, chanwoo, myungjoo.ham, kyungmin.park

Add debugfs interface to provide debugging information of devfreq device.
It contains 'devfreq_summary' entry to show the summary of registered
devfreq devices as following: And the additional debugfs file will be added.
- /sys/kernel/debug/devfreq/devfreq_summary

[For example on Exynos5422-based Odroid-XU3 board]
- In order to show the multiple governors on devfreq_summay result,
change the governor of devfreq0 from simple_ondemand to userspace.

$ cat /sys/kernel/debug/devfreq/devfreq_summary
dev name                       dev        parent dev governor        cur_freq     min_freq     max_freq
------------------------------ ---------- ---------- --------------- ------------ ------------ ------------
10c20000.memory-controller     devfreq0              userspace       165000000    165000000    825000000
soc:bus_wcore                  devfreq1              simple_ondemand 400000000    84000000     400000000
soc:bus_noc                    devfreq2   devfreq1   passive         100000000    67000000     100000000
soc:bus_fsys_apb               devfreq3   devfreq1   passive         200000000    100000000    200000000
soc:bus_fsys                   devfreq4   devfreq1   passive         200000000    100000000    200000000
soc:bus_fsys2                  devfreq5   devfreq1   passive         150000000    75000000     150000000
soc:bus_mfc                    devfreq6   devfreq1   passive         333000000    96000000     333000000
soc:bus_gen                    devfreq7   devfreq1   passive         267000000    89000000     267000000
soc:bus_peri                   devfreq8   devfreq1   passive         67000000     67000000     67000000
soc:bus_g2d                    devfreq9   devfreq1   passive         333000000    84000000     333000000
soc:bus_g2d_acp                devfreq10  devfreq1   passive         267000000    67000000     267000000
soc:bus_jpeg                   devfreq11  devfreq1   passive         300000000    75000000     300000000
soc:bus_jpeg_apb               devfreq12  devfreq1   passive         167000000    84000000     167000000
soc:bus_disp1_fimd             devfreq13  devfreq1   passive         200000000    120000000    200000000
soc:bus_disp1                  devfreq14  devfreq1   passive         300000000    120000000    300000000
soc:bus_gscl_scaler            devfreq15  devfreq1   passive         300000000    150000000    300000000
soc:bus_mscl                   devfreq16  devfreq1   passive         400000000    84000000     400000000

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq.c | 65 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index acd21345a070..d7177cc0a914 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/kmod.h>
 #include <linux/sched.h>
+#include <linux/debugfs.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -33,6 +34,7 @@
 #define HZ_PER_KHZ	1000
 
 static struct class *devfreq_class;
+static struct dentry *devfreq_debugfs;
 
 /*
  * devfreq core provides delayed work based load monitoring helper
@@ -1670,6 +1672,62 @@ static struct attribute *devfreq_attrs[] = {
 };
 ATTRIBUTE_GROUPS(devfreq);
 
+static int devfreq_summary_show(struct seq_file *s, void *data)
+{
+	struct devfreq *devfreq;
+	struct devfreq *parent_devfreq;
+	unsigned long cur_freq, min_freq, max_freq;
+
+	seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
+			"dev name",
+			"dev",
+			"parent dev",
+			"governor",
+			"cur_freq",
+			"min_freq",
+			"max_freq");
+	seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
+			"------------------------------",
+			"----------",
+			"----------",
+			"---------------",
+			"------------",
+			"------------",
+			"------------");
+
+	mutex_lock(&devfreq_list_lock);
+
+	list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+		if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
+							DEVFREQ_NAME_LEN)) {
+			struct devfreq_passive_data *data = devfreq->data;
+			parent_devfreq = data->parent;
+		} else {
+			parent_devfreq = NULL;
+		}
+#endif
+		mutex_lock(&devfreq->lock);
+		cur_freq = devfreq->previous_freq,
+		get_freq_range(devfreq, &min_freq, &max_freq);
+		mutex_unlock(&devfreq->lock);
+
+		seq_printf(s, "%-30s %-10s %-10s %-15s %-12ld %-12ld %-12ld\n",
+			dev_name(devfreq->dev.parent),
+			dev_name(&devfreq->dev),
+			parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
+			devfreq->governor_name,
+			cur_freq,
+			min_freq,
+			max_freq);
+	}
+
+	mutex_unlock(&devfreq_list_lock);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
+
 static int __init devfreq_init(void)
 {
 	devfreq_class = class_create(THIS_MODULE, "devfreq");
@@ -1686,6 +1744,13 @@ static int __init devfreq_init(void)
 	}
 	devfreq_class->dev_groups = devfreq_groups;
 
+	devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
+	if (PTR_ERR(devfreq_debugfs) != -ENODEV && IS_ERR(devfreq_debugfs))
+		pr_warn("%s: couldn't create debugfs dir\n", __FILE__);
+
+	debugfs_create_file("devfreq_summary", 0444, devfreq_debugfs, NULL,
+			&devfreq_summary_fops);
+
 	return 0;
 }
 subsys_initcall(devfreq_init);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] PM / devfreq: Add debugfs support with devfreq_summary file
  2019-12-26  6:07 ` [PATCH] PM / devfreq: Add debugfs support with devfreq_summary file Chanwoo Choi
@ 2019-12-30  3:26   ` Nathan Chancellor
  2019-12-30  5:13     ` Chanwoo Choi
  0 siblings, 1 reply; 3+ messages in thread
From: Nathan Chancellor @ 2019-12-30  3:26 UTC (permalink / raw)
  To: Chanwoo Choi
  Cc: linux-pm, linux-kernel, chanwoo, myungjoo.ham, kyungmin.park,
	clang-built-linux

Hi Chanwoo,

On Thu, Dec 26, 2019 at 03:07:49PM +0900, Chanwoo Choi wrote:
> Add debugfs interface to provide debugging information of devfreq device.
> It contains 'devfreq_summary' entry to show the summary of registered
> devfreq devices as following: And the additional debugfs file will be added.
> - /sys/kernel/debug/devfreq/devfreq_summary
> 
> [For example on Exynos5422-based Odroid-XU3 board]
> - In order to show the multiple governors on devfreq_summay result,
> change the governor of devfreq0 from simple_ondemand to userspace.
> 
> $ cat /sys/kernel/debug/devfreq/devfreq_summary
> dev name                       dev        parent dev governor        cur_freq     min_freq     max_freq
> ------------------------------ ---------- ---------- --------------- ------------ ------------ ------------
> 10c20000.memory-controller     devfreq0              userspace       165000000    165000000    825000000
> soc:bus_wcore                  devfreq1              simple_ondemand 400000000    84000000     400000000
> soc:bus_noc                    devfreq2   devfreq1   passive         100000000    67000000     100000000
> soc:bus_fsys_apb               devfreq3   devfreq1   passive         200000000    100000000    200000000
> soc:bus_fsys                   devfreq4   devfreq1   passive         200000000    100000000    200000000
> soc:bus_fsys2                  devfreq5   devfreq1   passive         150000000    75000000     150000000
> soc:bus_mfc                    devfreq6   devfreq1   passive         333000000    96000000     333000000
> soc:bus_gen                    devfreq7   devfreq1   passive         267000000    89000000     267000000
> soc:bus_peri                   devfreq8   devfreq1   passive         67000000     67000000     67000000
> soc:bus_g2d                    devfreq9   devfreq1   passive         333000000    84000000     333000000
> soc:bus_g2d_acp                devfreq10  devfreq1   passive         267000000    67000000     267000000
> soc:bus_jpeg                   devfreq11  devfreq1   passive         300000000    75000000     300000000
> soc:bus_jpeg_apb               devfreq12  devfreq1   passive         167000000    84000000     167000000
> soc:bus_disp1_fimd             devfreq13  devfreq1   passive         200000000    120000000    200000000
> soc:bus_disp1                  devfreq14  devfreq1   passive         300000000    120000000    300000000
> soc:bus_gscl_scaler            devfreq15  devfreq1   passive         300000000    150000000    300000000
> soc:bus_mscl                   devfreq16  devfreq1   passive         400000000    84000000     400000000
> 
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
>  drivers/devfreq/devfreq.c | 65 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 65 insertions(+)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index acd21345a070..d7177cc0a914 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -10,6 +10,7 @@
>  #include <linux/kernel.h>
>  #include <linux/kmod.h>
>  #include <linux/sched.h>
> +#include <linux/debugfs.h>
>  #include <linux/errno.h>
>  #include <linux/err.h>
>  #include <linux/init.h>
> @@ -33,6 +34,7 @@
>  #define HZ_PER_KHZ	1000
>  
>  static struct class *devfreq_class;
> +static struct dentry *devfreq_debugfs;
>  
>  /*
>   * devfreq core provides delayed work based load monitoring helper
> @@ -1670,6 +1672,62 @@ static struct attribute *devfreq_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(devfreq);
>  
> +static int devfreq_summary_show(struct seq_file *s, void *data)
> +{
> +	struct devfreq *devfreq;
> +	struct devfreq *parent_devfreq;
> +	unsigned long cur_freq, min_freq, max_freq;
> +
> +	seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
> +			"dev name",
> +			"dev",
> +			"parent dev",
> +			"governor",
> +			"cur_freq",
> +			"min_freq",
> +			"max_freq");
> +	seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
> +			"------------------------------",
> +			"----------",
> +			"----------",
> +			"---------------",
> +			"------------",
> +			"------------",
> +			"------------");
> +
> +	mutex_lock(&devfreq_list_lock);
> +

The 0day team has been doing builds with Clang and it pointed out that
when CONFIG_DEVFREQ_GOV_PASSIVE is unset, parent_devfreq is always
uninitialized. The else branch should probably be eliminated, moving the
parent_devfreq NULL initialization above the if preprocessor directive.

The full report is below.

> +	list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
> +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
> +		if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
> +							DEVFREQ_NAME_LEN)) {
> +			struct devfreq_passive_data *data = devfreq->data;
> +			parent_devfreq = data->parent;
> +		} else {
> +			parent_devfreq = NULL;
> +		}
> +#endif
> +		mutex_lock(&devfreq->lock);
> +		cur_freq = devfreq->previous_freq,
> +		get_freq_range(devfreq, &min_freq, &max_freq);
> +		mutex_unlock(&devfreq->lock);
> +
> +		seq_printf(s, "%-30s %-10s %-10s %-15s %-12ld %-12ld %-12ld\n",
> +			dev_name(devfreq->dev.parent),
> +			dev_name(&devfreq->dev),
> +			parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
> +			devfreq->governor_name,
> +			cur_freq,
> +			min_freq,
> +			max_freq);
> +	}
> +
> +	mutex_unlock(&devfreq_list_lock);
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
> +
>  static int __init devfreq_init(void)
>  {
>  	devfreq_class = class_create(THIS_MODULE, "devfreq");
> @@ -1686,6 +1744,13 @@ static int __init devfreq_init(void)
>  	}
>  	devfreq_class->dev_groups = devfreq_groups;
>  
> +	devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
> +	if (PTR_ERR(devfreq_debugfs) != -ENODEV && IS_ERR(devfreq_debugfs))
> +		pr_warn("%s: couldn't create debugfs dir\n", __FILE__);
> +
> +	debugfs_create_file("devfreq_summary", 0444, devfreq_debugfs, NULL,
> +			&devfreq_summary_fops);
> +
>  	return 0;
>  }
>  subsys_initcall(devfreq_init);
> -- 
> 2.17.1
> 

Cheers,
Nathan

On Thu, Dec 26, 2019 at 11:47:26PM +0800, kbuild test robot wrote:
> CC: kbuild-all@lists.01.org
> In-Reply-To: <20191226060749.13881-1-cw00.choi@samsung.com>
> References: <20191226060749.13881-1-cw00.choi@samsung.com>
> TO: Chanwoo Choi <cw00.choi@samsung.com>
> 
> Hi Chanwoo,
> 
> I love your patch! Perhaps something to improve:
> 
> [auto build test WARNING on linux/master]
> [also build test WARNING on linus/master v5.5-rc3 next-20191220]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system. BTW, we also suggest to use '--base' option to specify the
> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
> 
> url:    https://github.com/0day-ci/linux/commits/Chanwoo-Choi/PM-devfreq-Add-debugfs-support-with-devfreq_summary-file/20191226-140227
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 1522d9da40bdfe502c91163e6d769332897201fa
> config: arm64-defconfig (attached as .config)
> compiler: clang version 10.0.0 (git://gitmirror/llvm_project c5b4a2386b51a18daad7e42040c685c2e9708c47)
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=arm64 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> drivers/devfreq/devfreq.c:1653:4: warning: variable 'parent_devfreq' is uninitialized when used here [-Wuninitialized]
>                            parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
>                            ^~~~~~~~~~~~~~
>    drivers/devfreq/devfreq.c:1613:32: note: initialize the variable 'parent_devfreq' to silence this warning
>            struct devfreq *parent_devfreq;
>                                          ^
>                                           = NULL
>    1 warning generated.
> 
> vim +/parent_devfreq +1653 drivers/devfreq/devfreq.c
> 
>   1609	
>   1610	static int devfreq_summary_show(struct seq_file *s, void *data)
>   1611	{
>   1612		struct devfreq *devfreq;
>   1613		struct devfreq *parent_devfreq;
>   1614		unsigned long cur_freq, min_freq, max_freq;
>   1615	
>   1616		seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
>   1617				"dev name",
>   1618				"dev",
>   1619				"parent dev",
>   1620				"governor",
>   1621				"cur_freq",
>   1622				"min_freq",
>   1623				"max_freq");
>   1624		seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
>   1625				"------------------------------",
>   1626				"----------",
>   1627				"----------",
>   1628				"---------------",
>   1629				"------------",
>   1630				"------------",
>   1631				"------------");
>   1632	
>   1633		mutex_lock(&devfreq_list_lock);
>   1634	
>   1635		list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
>   1636	#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
>   1637			if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
>   1638								DEVFREQ_NAME_LEN)) {
>   1639				struct devfreq_passive_data *data = devfreq->data;
>   1640				parent_devfreq = data->parent;
>   1641			} else {
>   1642				parent_devfreq = NULL;
>   1643			}
>   1644	#endif
>   1645			mutex_lock(&devfreq->lock);
>   1646			cur_freq = devfreq->previous_freq,
>   1647			get_freq_range(devfreq, &min_freq, &max_freq);
>   1648			mutex_unlock(&devfreq->lock);
>   1649	
>   1650			seq_printf(s, "%-30s %-10s %-10s %-15s %-12ld %-12ld %-12ld\n",
>   1651				dev_name(devfreq->dev.parent),
>   1652				dev_name(&devfreq->dev),
> > 1653				parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
>   1654				devfreq->governor_name,
>   1655				cur_freq,
>   1656				min_freq,
>   1657				max_freq);
>   1658		}
>   1659	
>   1660		mutex_unlock(&devfreq_list_lock);
>   1661	
>   1662		return 0;
>   1663	}
>   1664	DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
>   1665	
> 
> ---
> 0-DAY kernel test infrastructure                 Open Source Technology Center
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] PM / devfreq: Add debugfs support with devfreq_summary file
  2019-12-30  3:26   ` Nathan Chancellor
@ 2019-12-30  5:13     ` Chanwoo Choi
  0 siblings, 0 replies; 3+ messages in thread
From: Chanwoo Choi @ 2019-12-30  5:13 UTC (permalink / raw)
  To: Nathan Chancellor
  Cc: linux-pm, linux-kernel, chanwoo, myungjoo.ham, kyungmin.park,
	clang-built-linux

Hi Nathan,

On 12/30/19 12:26 PM, Nathan Chancellor wrote:
> Hi Chanwoo,
> 
> On Thu, Dec 26, 2019 at 03:07:49PM +0900, Chanwoo Choi wrote:
>> Add debugfs interface to provide debugging information of devfreq device.
>> It contains 'devfreq_summary' entry to show the summary of registered
>> devfreq devices as following: And the additional debugfs file will be added.
>> - /sys/kernel/debug/devfreq/devfreq_summary
>>
>> [For example on Exynos5422-based Odroid-XU3 board]
>> - In order to show the multiple governors on devfreq_summay result,
>> change the governor of devfreq0 from simple_ondemand to userspace.
>>
>> $ cat /sys/kernel/debug/devfreq/devfreq_summary
>> dev name                       dev        parent dev governor        cur_freq     min_freq     max_freq
>> ------------------------------ ---------- ---------- --------------- ------------ ------------ ------------
>> 10c20000.memory-controller     devfreq0              userspace       165000000    165000000    825000000
>> soc:bus_wcore                  devfreq1              simple_ondemand 400000000    84000000     400000000
>> soc:bus_noc                    devfreq2   devfreq1   passive         100000000    67000000     100000000
>> soc:bus_fsys_apb               devfreq3   devfreq1   passive         200000000    100000000    200000000
>> soc:bus_fsys                   devfreq4   devfreq1   passive         200000000    100000000    200000000
>> soc:bus_fsys2                  devfreq5   devfreq1   passive         150000000    75000000     150000000
>> soc:bus_mfc                    devfreq6   devfreq1   passive         333000000    96000000     333000000
>> soc:bus_gen                    devfreq7   devfreq1   passive         267000000    89000000     267000000
>> soc:bus_peri                   devfreq8   devfreq1   passive         67000000     67000000     67000000
>> soc:bus_g2d                    devfreq9   devfreq1   passive         333000000    84000000     333000000
>> soc:bus_g2d_acp                devfreq10  devfreq1   passive         267000000    67000000     267000000
>> soc:bus_jpeg                   devfreq11  devfreq1   passive         300000000    75000000     300000000
>> soc:bus_jpeg_apb               devfreq12  devfreq1   passive         167000000    84000000     167000000
>> soc:bus_disp1_fimd             devfreq13  devfreq1   passive         200000000    120000000    200000000
>> soc:bus_disp1                  devfreq14  devfreq1   passive         300000000    120000000    300000000
>> soc:bus_gscl_scaler            devfreq15  devfreq1   passive         300000000    150000000    300000000
>> soc:bus_mscl                   devfreq16  devfreq1   passive         400000000    84000000     400000000
>>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> ---
>>  drivers/devfreq/devfreq.c | 65 +++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 65 insertions(+)
>>
>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>> index acd21345a070..d7177cc0a914 100644
>> --- a/drivers/devfreq/devfreq.c
>> +++ b/drivers/devfreq/devfreq.c
>> @@ -10,6 +10,7 @@
>>  #include <linux/kernel.h>
>>  #include <linux/kmod.h>
>>  #include <linux/sched.h>
>> +#include <linux/debugfs.h>
>>  #include <linux/errno.h>
>>  #include <linux/err.h>
>>  #include <linux/init.h>
>> @@ -33,6 +34,7 @@
>>  #define HZ_PER_KHZ	1000
>>  
>>  static struct class *devfreq_class;
>> +static struct dentry *devfreq_debugfs;
>>  
>>  /*
>>   * devfreq core provides delayed work based load monitoring helper
>> @@ -1670,6 +1672,62 @@ static struct attribute *devfreq_attrs[] = {
>>  };
>>  ATTRIBUTE_GROUPS(devfreq);
>>  
>> +static int devfreq_summary_show(struct seq_file *s, void *data)
>> +{
>> +	struct devfreq *devfreq;
>> +	struct devfreq *parent_devfreq;
>> +	unsigned long cur_freq, min_freq, max_freq;
>> +
>> +	seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
>> +			"dev name",
>> +			"dev",
>> +			"parent dev",
>> +			"governor",
>> +			"cur_freq",
>> +			"min_freq",
>> +			"max_freq");
>> +	seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
>> +			"------------------------------",
>> +			"----------",
>> +			"----------",
>> +			"---------------",
>> +			"------------",
>> +			"------------",
>> +			"------------");
>> +
>> +	mutex_lock(&devfreq_list_lock);
>> +
> 
> The 0day team has been doing builds with Clang and it pointed out that
> when CONFIG_DEVFREQ_GOV_PASSIVE is unset, parent_devfreq is always
> uninitialized. The else branch should probably be eliminated, moving the
> parent_devfreq NULL initialization above the if preprocessor directive.
> 
> The full report is below.

Thanks for the report. I'll fix it as following:

struct devfreq *parent_devfreq = NULL;

> 
>> +	list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
>> +#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
>> +		if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
>> +							DEVFREQ_NAME_LEN)) {
>> +			struct devfreq_passive_data *data = devfreq->data;
>> +			parent_devfreq = data->parent;
>> +		} else {
>> +			parent_devfreq = NULL;
>> +		}
>> +#endif
>> +		mutex_lock(&devfreq->lock);
>> +		cur_freq = devfreq->previous_freq,
>> +		get_freq_range(devfreq, &min_freq, &max_freq);
>> +		mutex_unlock(&devfreq->lock);
>> +
>> +		seq_printf(s, "%-30s %-10s %-10s %-15s %-12ld %-12ld %-12ld\n",
>> +			dev_name(devfreq->dev.parent),
>> +			dev_name(&devfreq->dev),
>> +			parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
>> +			devfreq->governor_name,
>> +			cur_freq,
>> +			min_freq,
>> +			max_freq);
>> +	}
>> +
>> +	mutex_unlock(&devfreq_list_lock);
>> +
>> +	return 0;
>> +}
>> +DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
>> +
>>  static int __init devfreq_init(void)
>>  {
>>  	devfreq_class = class_create(THIS_MODULE, "devfreq");
>> @@ -1686,6 +1744,13 @@ static int __init devfreq_init(void)
>>  	}
>>  	devfreq_class->dev_groups = devfreq_groups;
>>  
>> +	devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
>> +	if (PTR_ERR(devfreq_debugfs) != -ENODEV && IS_ERR(devfreq_debugfs))
>> +		pr_warn("%s: couldn't create debugfs dir\n", __FILE__);
>> +
>> +	debugfs_create_file("devfreq_summary", 0444, devfreq_debugfs, NULL,
>> +			&devfreq_summary_fops);
>> +
>>  	return 0;
>>  }
>>  subsys_initcall(devfreq_init);
>> -- 
>> 2.17.1
>>
> 
> Cheers,
> Nathan
> 
> On Thu, Dec 26, 2019 at 11:47:26PM +0800, kbuild test robot wrote:
>> CC: kbuild-all@lists.01.org
>> In-Reply-To: <20191226060749.13881-1-cw00.choi@samsung.com>
>> References: <20191226060749.13881-1-cw00.choi@samsung.com>
>> TO: Chanwoo Choi <cw00.choi@samsung.com>
>>
>> Hi Chanwoo,
>>
>> I love your patch! Perhaps something to improve:
>>
>> [auto build test WARNING on linux/master]
>> [also build test WARNING on linus/master v5.5-rc3 next-20191220]
>> [if your patch is applied to the wrong git tree, please drop us a note to help
>> improve the system. BTW, we also suggest to use '--base' option to specify the
>> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
>>
>> url:    https://protect2.fireeye.com/url?k=aa57311e-f7cb307e-aa56ba51-0cc47a31307c-5e67a2de952cf65a&u=https://github.com/0day-ci/linux/commits/Chanwoo-Choi/PM-devfreq-Add-debugfs-support-with-devfreq_summary-file/20191226-140227
>> base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 1522d9da40bdfe502c91163e6d769332897201fa
>> config: arm64-defconfig (attached as .config)
>> compiler: clang version 10.0.0 (git://gitmirror/llvm_project c5b4a2386b51a18daad7e42040c685c2e9708c47)
>> reproduce:
>>         wget https://protect2.fireeye.com/url?k=e9857e19-b4197f79-e984f556-0cc47a31307c-e0c94321f498a093&u=https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>>         chmod +x ~/bin/make.cross
>>         # save the attached .config to linux build tree
>>         make.cross ARCH=arm64 
>>
>> If you fix the issue, kindly add following tag
>> Reported-by: kbuild test robot <lkp@intel.com>
>>
>> All warnings (new ones prefixed by >>):
>>
>>>> drivers/devfreq/devfreq.c:1653:4: warning: variable 'parent_devfreq' is uninitialized when used here [-Wuninitialized]
>>                            parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
>>                            ^~~~~~~~~~~~~~
>>    drivers/devfreq/devfreq.c:1613:32: note: initialize the variable 'parent_devfreq' to silence this warning
>>            struct devfreq *parent_devfreq;
>>                                          ^
>>                                           = NULL
>>    1 warning generated.
>>
>> vim +/parent_devfreq +1653 drivers/devfreq/devfreq.c
>>
>>   1609	
>>   1610	static int devfreq_summary_show(struct seq_file *s, void *data)
>>   1611	{
>>   1612		struct devfreq *devfreq;
>>   1613		struct devfreq *parent_devfreq;
>>   1614		unsigned long cur_freq, min_freq, max_freq;
>>   1615	
>>   1616		seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
>>   1617				"dev name",
>>   1618				"dev",
>>   1619				"parent dev",
>>   1620				"governor",
>>   1621				"cur_freq",
>>   1622				"min_freq",
>>   1623				"max_freq");
>>   1624		seq_printf(s, "%-30s %-10s %-10s %-15s %-12s %-12s %-12s\n",
>>   1625				"------------------------------",
>>   1626				"----------",
>>   1627				"----------",
>>   1628				"---------------",
>>   1629				"------------",
>>   1630				"------------",
>>   1631				"------------");
>>   1632	
>>   1633		mutex_lock(&devfreq_list_lock);
>>   1634	
>>   1635		list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
>>   1636	#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
>>   1637			if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
>>   1638								DEVFREQ_NAME_LEN)) {
>>   1639				struct devfreq_passive_data *data = devfreq->data;
>>   1640				parent_devfreq = data->parent;
>>   1641			} else {
>>   1642				parent_devfreq = NULL;
>>   1643			}
>>   1644	#endif
>>   1645			mutex_lock(&devfreq->lock);
>>   1646			cur_freq = devfreq->previous_freq,
>>   1647			get_freq_range(devfreq, &min_freq, &max_freq);
>>   1648			mutex_unlock(&devfreq->lock);
>>   1649	
>>   1650			seq_printf(s, "%-30s %-10s %-10s %-15s %-12ld %-12ld %-12ld\n",
>>   1651				dev_name(devfreq->dev.parent),
>>   1652				dev_name(&devfreq->dev),
>>> 1653				parent_devfreq ? dev_name(&parent_devfreq->dev) : "",
>>   1654				devfreq->governor_name,
>>   1655				cur_freq,
>>   1656				min_freq,
>>   1657				max_freq);
>>   1658		}
>>   1659	
>>   1660		mutex_unlock(&devfreq_list_lock);
>>   1661	
>>   1662		return 0;
>>   1663	}
>>   1664	DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
>>   1665	
>>
>> ---
>> 0-DAY kernel test infrastructure                 Open Source Technology Center
>> https://protect2.fireeye.com/url?k=f6f1d925-ab6dd845-f6f0526a-0cc47a31307c-7e8a6c295935ff12&u=https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
>>
> 
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-12-30  5:06 UTC | newest]

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2019-12-26  6:07 ` [PATCH] PM / devfreq: Add debugfs support with devfreq_summary file Chanwoo Choi
2019-12-30  3:26   ` Nathan Chancellor
2019-12-30  5:13     ` Chanwoo Choi

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