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SubjectRe: [PATCH 7/7] devfreq: move statistics to separate struct
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Hi Bartlomiej,

On 11/15/19 3:01 AM, Bartlomiej Zolnierkiewicz wrote:
>
> Hi Chanwoo,
>
> On 11/14/19 2:52 AM, Chanwoo Choi wrote:
>> Hi Kamil,
>>
>> The 'freq_table' and 'max_state' in the devfreq_dev_profile
>> were used in the ARM Mali device driver[1][2][3]. Although ARM Mali
>> device driver was posted to mainline kernel, they used
>> them for a long time. It means that this patch break
>> the compatibility. The ARM Mali drivers are very
>> important devfreq device driver.
>
> This argument is not a a technical one and the official upstream
> kernel policy is to not depend on out-of-tree drivers.
>
> Besides the ARM Mali drivers are full of code like:
>
> #if LINUX_VERSION_CODE >= KERNEL_VERSION(x, y, z)
> ...
> #else
> ...
> #endif
>
> so few more instances of similar code won't do any harm.. ;-)
>
>> [1] https://developer.arm.com/tools-and-software/graphics-and-gaming/mali-drivers/bifrost-kernel#
>> [2] https://developer.arm.com/tools-and-software/graphics-and-gaming/mali-drivers/midgard-kernel
>> [3] https://developer.arm.com/tools-and-software/graphics-and-gaming/mali-drivers/utgard-kernel
>
> I took a look at ARM Mali drivers source code anyway and I fail to
> see a rationale behind their behavior of doing 'freq_table' and
> 'max_state' initialization in the driver itself (instead of leaving
> it up to the devfreq core code, like all in-kernel drivers are doing
> already).
>
> Could you please explain rationale behind ARM Mali drivers' special
> needs?
>
> [ Both ARM Mali and devfreq core code are using generic PM OPP code
> these days to do 'freq_table' and 'max_state' initialization, the
> only difference seems to be that ARM Mali creates the frequency
> table in the descending order (but there also seems to be no real
> need for it). ]
>
> Maybe this is an opportunity to simplify also the ARM Mali driver?

OK. I agree to simplify them on this time.
For touching the 'freq_table' and 'max_state', need to fix
the descending order of freq_table.

The partition_enable_ops() in the drivers/thermal/devfreq_cooling.c
requires the descending order of freq_table. Have to change it by using
the ascending time or support both ascending and descending order for freq_table.

1. Move freq_table, max_state of devfreq_dev_profile to struct devfreq
2. Edit partition_enable_ops() in the drivers/thermal/devfreq_cooling.c
by using ascending order instead of descending order.

>
>> Also, the devfreq device driver specifies their own
>> information and data into devfreq_dev_profile structure
>> before registering the devfreq device with devfreq_add_device().
>> This patch breaks the basic usage rule of devfreq_dev_profile structure.
>
> Well, 'struct devfreq_stats *stats' can be trivially moved out of
> 'struct devfreq_profile' to 'struct devfreq' if you prefer it that
> way..
>
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics
>
>> So, I can't agree this patch. Not ack.
>>
>> Regards,
>> Chanwoo Choi
>>
>> On 11/13/19 6:13 PM, Kamil Konieczny wrote:
>>> Count time and transitions between devfreq frequencies in separate struct
>>> for improved code readability and maintenance.
>>>
>>> Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
>>> ---
>>> drivers/devfreq/devfreq.c | 156 ++++++++++++++++-------------
>>> drivers/devfreq/exynos-bus.c | 6 +-
>>> drivers/devfreq/governor_passive.c | 26 +++--
>>> include/linux/devfreq.h | 43 ++++----
>>> 4 files changed, 129 insertions(+), 102 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>>> index d79412b0de59..d85867a91230 100644
>>> --- a/drivers/devfreq/devfreq.c
>>> +++ b/drivers/devfreq/devfreq.c
>>> @@ -105,10 +105,11 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq)
>>> */
>>> static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
>>> {
>>> + struct devfreq_stats *stats = devfreq->profile->stats;
>>> int lev;
>>>
>>> - for (lev = 0; lev < devfreq->profile->max_state; lev++)
>>> - if (freq == devfreq->profile->freq_table[lev])
>>> + for (lev = 0; lev < stats->max_state; lev++)
>>> + if (freq == stats->freq_table[lev])
>>> return lev;
>>>
>>> return -EINVAL;
>>> @@ -117,56 +118,64 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
>>> static int set_freq_table(struct devfreq *devfreq)
>>> {
>>> struct devfreq_dev_profile *profile = devfreq->profile;
>>> + struct devfreq_stats *stats;
>>> struct dev_pm_opp *opp;
>>> unsigned long freq;
>>> - int i, count;
>>> + int i, count, err = -ENOMEM;
>>>
>>> /* Initialize the freq_table from OPP table */
>>> count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
>>> if (count <= 0)
>>> return -EINVAL;
>>>
>>> - profile->max_state = count;
>>> - profile->freq_table = devm_kcalloc(devfreq->dev.parent,
>>> - count,
>>> - sizeof(*profile->freq_table),
>>> - GFP_KERNEL);
>>> - if (!profile->freq_table) {
>>> - profile->max_state = 0;
>>> + stats = devm_kzalloc(devfreq->dev.parent,
>>> + sizeof(struct devfreq_stats), GFP_KERNEL);
>>> + if (!stats)
>>> return -ENOMEM;
>>> - }
>>>
>>> - for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
>>> + profile->stats = stats;
>>> + stats->max_state = count;
>>> + stats->freq_table = devm_kcalloc(devfreq->dev.parent,
>>> + count,
>>> + sizeof(*stats->freq_table),
>>> + GFP_KERNEL);
>>> + if (!stats->freq_table)
>>> + goto err_no_mem;
>>> +
>>> + for (i = 0, freq = 0; i < count; i++, freq++) {
>>> opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
>>> if (IS_ERR(opp)) {
>>> - devm_kfree(devfreq->dev.parent, profile->freq_table);
>>> - profile->max_state = 0;
>>> - return PTR_ERR(opp);
>>> + devm_kfree(devfreq->dev.parent, stats->freq_table);
>>> + stats->max_state = 0;
>>> + err = PTR_ERR(opp);
>>> + goto err_no_mem;
>>> }
>>> dev_pm_opp_put(opp);
>>> - profile->freq_table[i] = freq;
>>> + stats->freq_table[i] = freq;
>>> }
>>>
>>> - profile->trans_table = devm_kzalloc(devfreq->dev.parent,
>>> - array3_size(sizeof(unsigned int),
>>> - count, count),
>>> - GFP_KERNEL);
>>> - if (!profile->trans_table)
>>> + stats->trans_table = devm_kzalloc(devfreq->dev.parent,
>>> + array3_size(sizeof(unsigned int),
>>> + count, count),
>>> + GFP_KERNEL);
>>> + if (!stats->trans_table)
>>> goto err_no_mem;
>>>
>>> - profile->time_in_state = devm_kcalloc(devfreq->dev.parent, count,
>>> - sizeof(*profile->time_in_state),
>>> - GFP_KERNEL);
>>> - if (!profile->time_in_state)
>>> + stats->time_in_state = devm_kcalloc(devfreq->dev.parent, count,
>>> + sizeof(*stats->time_in_state),
>>> + GFP_KERNEL);
>>> + if (!stats->time_in_state)
>>> goto err_no_mem;
>>>
>>> - profile->last_time = get_jiffies_64();
>>> - spin_lock_init(&profile->stats_lock);
>>> + stats->last_time = get_jiffies_64();
>>> + spin_lock_init(&stats->stats_lock);
>>>
>>> return 0;
>>> err_no_mem:
>>> - profile->max_state = 0;
>>> - return -ENOMEM;
>>> + stats->max_state = 0;
>>> + devm_kfree(devfreq->dev.parent, profile->stats);
>>> + profile->stats = NULL;
>>> + return err;
>>> }
>>>
>>> /**
>>> @@ -176,7 +185,7 @@ static int set_freq_table(struct devfreq *devfreq)
>>> */
>>> int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
>>> {
>>> - struct devfreq_dev_profile *profile = devfreq->profile;
>>> + struct devfreq_stats *stats = devfreq->profile->stats;
>>> unsigned long long cur_time;
>>> int lev, prev_lev, ret = 0;
>>>
>>> @@ -184,22 +193,21 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
>>>
>>> /* Immediately exit if previous_freq is not initialized yet. */
>>> if (!devfreq->previous_freq) {
>>> - spin_lock(&profile->stats_lock);
>>> - profile->last_time = cur_time;
>>> - spin_unlock(&profile->stats_lock);
>>> + spin_lock(&stats->stats_lock);
>>> + stats->last_time = cur_time;
>>> + spin_unlock(&stats->stats_lock);
>>> return 0;
>>> }
>>>
>>> prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
>>>
>>> - spin_lock(&profile->stats_lock);
>>> + spin_lock(&stats->stats_lock);
>>> if (prev_lev < 0) {
>>> ret = prev_lev;
>>> goto out;
>>> }
>>>
>>> - profile->time_in_state[prev_lev] +=
>>> - cur_time - profile->last_time;
>>> + stats->time_in_state[prev_lev] += cur_time - stats->last_time;
>>> lev = devfreq_get_freq_level(devfreq, freq);
>>> if (lev < 0) {
>>> ret = lev;
>>> @@ -207,14 +215,14 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
>>> }
>>>
>>> if (lev != prev_lev) {
>>> - profile->trans_table[(prev_lev *
>>> - profile->max_state) + lev]++;
>>> - profile->total_trans++;
>>> + stats->trans_table[(prev_lev *
>>> + stats->max_state) + lev]++;
>>> + stats->total_trans++;
>>> }
>>>
>>> out:
>>> - profile->last_time = cur_time;
>>> - spin_unlock(&profile->stats_lock);
>>> + stats->last_time = cur_time;
>>> + spin_unlock(&stats->stats_lock);
>>> return ret;
>>> }
>>> EXPORT_SYMBOL(devfreq_update_status);
>>> @@ -504,9 +512,9 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
>>> queue_delayed_work(devfreq_wq, &devfreq->work,
>>> msecs_to_jiffies(profile->polling_ms));
>>>
>>> - spin_lock(&profile->stats_lock);
>>> - profile->last_time = get_jiffies_64();
>>> - spin_unlock(&profile->stats_lock);
>>> + spin_lock(&profile->stats->stats_lock);
>>> + profile->stats->last_time = get_jiffies_64();
>>> + spin_unlock(&profile->stats->stats_lock);
>>> devfreq->stop_polling = false;
>>>
>>> if (profile->get_cur_freq &&
>>> @@ -677,7 +685,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
>>> devfreq->data = data;
>>> devfreq->nb.notifier_call = devfreq_notifier_call;
>>>
>>> - if (!profile->max_state && !profile->freq_table) {
>>> + if (!profile->stats) {
>>> mutex_unlock(&devfreq->lock);
>>> err = set_freq_table(devfreq);
>>> if (err < 0)
>>> @@ -1282,6 +1290,7 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
>>> const char *buf, size_t count)
>>> {
>>> struct devfreq *df = to_devfreq(dev);
>>> + struct devfreq_stats *stats = df->profile->stats;
>>> unsigned long value;
>>> int ret;
>>>
>>> @@ -1297,13 +1306,13 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
>>> goto unlock;
>>> }
>>> } else {
>>> - unsigned long *freq_table = df->profile->freq_table;
>>> + unsigned long *freq_table = stats->freq_table;
>>>
>>> /* Get minimum frequency according to sorting order */
>>> - if (freq_table[0] < freq_table[df->profile->max_state - 1])
>>> + if (freq_table[0] < freq_table[stats->max_state - 1])
>>> value = freq_table[0];
>>> else
>>> - value = freq_table[df->profile->max_state - 1];
>>> + value = freq_table[stats->max_state - 1];
>>> }
>>>
>>> df->min_freq = value;
>>> @@ -1326,6 +1335,7 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
>>> const char *buf, size_t count)
>>> {
>>> struct devfreq *df = to_devfreq(dev);
>>> + struct devfreq_stats *stats = df->profile->stats;
>>> unsigned long value;
>>> int ret;
>>>
>>> @@ -1341,11 +1351,11 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
>>> goto unlock;
>>> }
>>> } else {
>>> - unsigned long *freq_table = df->profile->freq_table;
>>> + unsigned long *freq_table = stats->freq_table;
>>>
>>> /* Get maximum frequency according to sorting order */
>>> - if (freq_table[0] < freq_table[df->profile->max_state - 1])
>>> - value = freq_table[df->profile->max_state - 1];
>>> + if (freq_table[0] < freq_table[stats->max_state - 1])
>>> + value = freq_table[stats->max_state - 1];
>>> else
>>> value = freq_table[0];
>>> }
>>> @@ -1373,14 +1383,15 @@ static ssize_t available_frequencies_show(struct device *d,
>>> char *buf)
>>> {
>>> struct devfreq *df = to_devfreq(d);
>>> + struct devfreq_stats *stats = df->profile->stats;
>>> ssize_t count = 0;
>>> int i;
>>>
>>> mutex_lock(&df->lock);
>>>
>>> - for (i = 0; i < df->profile->max_state; i++)
>>> + for (i = 0; i < stats->max_state; i++)
>>> count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
>>> - "%lu ", df->profile->freq_table[i]);
>>> + "%lu ", stats->freq_table[i]);
>>>
>>> mutex_unlock(&df->lock);
>>> /* Truncate the trailing space */
>>> @@ -1398,9 +1409,10 @@ static ssize_t trans_stat_show(struct device *dev,
>>> {
>>> struct devfreq *devfreq = to_devfreq(dev);
>>> struct devfreq_dev_profile *profile = devfreq->profile;
>>> + struct devfreq_stats *stats = profile->stats;
>>> + unsigned int max_state = stats->max_state;
>>> ssize_t len;
>>> int i, j;
>>> - unsigned int max_state = profile->max_state;
>>>
>>> if (!devfreq->stop_polling &&
>>> devfreq_update_status(devfreq, devfreq->previous_freq))
>>> @@ -1411,45 +1423,45 @@ static ssize_t trans_stat_show(struct device *dev,
>>> len = sprintf(buf, " From : To\n");
>>> len += sprintf(buf + len, " :");
>>>
>>> - spin_lock(&profile->stats_lock);
>>> + spin_lock(&stats->stats_lock);
>>> for (i = 0; i < max_state; i++)
>>> len += sprintf(buf + len, "%10lu",
>>> - profile->freq_table[i]);
>>> + stats->freq_table[i]);
>>>
>>> len += sprintf(buf + len, " time(ms)\n");
>>>
>>> for (i = 0; i < max_state; i++) {
>>> - if (profile->freq_table[i] == devfreq->previous_freq)
>>> + if (stats->freq_table[i] == devfreq->previous_freq)
>>> len += sprintf(buf + len, "*");
>>> else
>>> len += sprintf(buf + len, " ");
>>>
>>> len += sprintf(buf + len, "%10lu:",
>>> - profile->freq_table[i]);
>>> + stats->freq_table[i]);
>>> for (j = 0; j < max_state; j++)
>>> len += sprintf(buf + len, "%10u",
>>> - profile->trans_table[(i * max_state) + j]);
>>> + stats->trans_table[(i * max_state) + j]);
>>> len += sprintf(buf + len, "%10llu\n", (u64)
>>> - jiffies64_to_msecs(profile->time_in_state[i]));
>>> + jiffies64_to_msecs(stats->time_in_state[i]));
>>> }
>>>
>>> len += sprintf(buf + len, "Total transition : %u\n",
>>> - profile->total_trans);
>>> - spin_unlock(&profile->stats_lock);
>>> + stats->total_trans);
>>> + spin_unlock(&stats->stats_lock);
>>> return len;
>>> }
>>> static DEVICE_ATTR_RO(trans_stat);
>>>
>>> -static void defvreq_stats_clear_table(struct devfreq_dev_profile *profile)
>>> +static void defvreq_stats_clear_table(struct devfreq_stats *stats)
>>> {
>>> - unsigned int count = profile->max_state;
>>> -
>>> - spin_lock(&profile->stats_lock);
>>> - memset(profile->time_in_state, 0, count * sizeof(u64));
>>> - memset(profile->trans_table, 0, count * count * sizeof(int));
>>> - profile->last_time = get_jiffies_64();
>>> - profile->total_trans = 0;
>>> - spin_unlock(&profile->stats_lock);
>>> + unsigned int count = stats->max_state;
>>> +
>>> + spin_lock(&stats->stats_lock);
>>> + memset(stats->time_in_state, 0, count * sizeof(u64));
>>> + memset(stats->trans_table, 0, count * count * sizeof(int));
>>> + stats->last_time = get_jiffies_64();
>>> + stats->total_trans = 0;
>>> + spin_unlock(&stats->stats_lock);
>>> }
>>>
>>> static ssize_t trans_reset_store(struct device *dev,
>>> @@ -1459,7 +1471,7 @@ static ssize_t trans_reset_store(struct device *dev,
>>> {
>>> struct devfreq *devfreq = to_devfreq(dev);
>>>
>>> - defvreq_stats_clear_table(devfreq->profile);
>>> + defvreq_stats_clear_table(devfreq->profile->stats);
>>>
>>> return count;
>>> }
>>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
>>> index d9f377912c10..b212aae2bb3e 100644
>>> --- a/drivers/devfreq/exynos-bus.c
>>> +++ b/drivers/devfreq/exynos-bus.c
>>> @@ -496,9 +496,9 @@ static int exynos_bus_probe(struct platform_device *pdev)
>>> }
>>>
>>> out:
>>> - max_state = bus->devfreq->profile->max_state;
>>> - min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
>>> - max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
>>> + max_state = profile->stats->max_state;
>>> + min_freq = (profile->stats->freq_table[0] / 1000);
>>> + max_freq = (profile->stats->freq_table[max_state - 1] / 1000);
>>> pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
>>> dev_name(dev), min_freq, max_freq);
>>>
>>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
>>> index 58308948b863..b2d87a88335c 100644
>>> --- a/drivers/devfreq/governor_passive.c
>>> +++ b/drivers/devfreq/governor_passive.c
>>> @@ -18,6 +18,8 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
>>> struct devfreq_passive_data *p_data
>>> = (struct devfreq_passive_data *)devfreq->data;
>>> struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
>>> + struct devfreq_stats *parent_stats = parent_devfreq->profile->stats;
>>> + struct devfreq_stats *stats;
>>> unsigned long child_freq = ULONG_MAX;
>>> struct dev_pm_opp *opp;
>>> int i, count, ret = 0;
>>> @@ -47,10 +49,14 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
>>> * device. And then the index is used for getting the suitable
>>> * new frequency for passive devfreq device.
>>> */
>>> - if (!devfreq->profile || !devfreq->profile->freq_table
>>> - || devfreq->profile->max_state <= 0)
>>> + if (!devfreq->profile || !devfreq->profile->stats ||
>>> + devfreq->profile->stats->max_state <= 0 ||
>>> + !parent_devfreq->profile || !parent_devfreq->profile->stats ||
>>> + parent_devfreq->profile->stats->max_state <= 0)
>>> return -EINVAL;
>>>
>>> + stats = devfreq->profile->stats;
>>> + parent_stats = parent_devfreq->profile->stats;
>>> /*
>>> * The passive governor have to get the correct frequency from OPP
>>> * list of parent device. Because in this case, *freq is temporary
>>> @@ -68,21 +74,21 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
>>> * Get the OPP table's index of decided freqeuncy by governor
>>> * of parent device.
>>> */
>>> - for (i = 0; i < parent_devfreq->profile->max_state; i++)
>>> - if (parent_devfreq->profile->freq_table[i] == *freq)
>>> + for (i = 0; i < parent_stats->max_state; i++)
>>> + if (parent_stats->freq_table[i] == *freq)
>>> break;
>>>
>>> - if (i == parent_devfreq->profile->max_state) {
>>> + if (i == parent_stats->max_state) {
>>> ret = -EINVAL;
>>> goto out;
>>> }
>>>
>>> /* Get the suitable frequency by using index of parent device. */
>>> - if (i < devfreq->profile->max_state) {
>>> - child_freq = devfreq->profile->freq_table[i];
>>> + if (i < stats->max_state) {
>>> + child_freq = stats->freq_table[i];
>>> } else {
>>> - count = devfreq->profile->max_state;
>>> - child_freq = devfreq->profile->freq_table[count - 1];
>>> + count = stats->max_state;
>>> + child_freq = stats->freq_table[count - 1];
>>> }
>>>
>>> /* Return the suitable frequency for passive device. */
>>> @@ -109,7 +115,7 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
>>> if (ret < 0)
>>> goto out;
>>>
>>> - if (devfreq->profile->freq_table
>>> + if (devfreq->profile->stats
>>> && (devfreq_update_status(devfreq, freq)))
>>> dev_err(&devfreq->dev,
>>> "Couldn't update frequency transition information.\n");
>>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
>>> index 4ceb2a517a9c..8459af1a1583 100644
>>> --- a/include/linux/devfreq.h
>>> +++ b/include/linux/devfreq.h
>>> @@ -64,6 +64,30 @@ struct devfreq_dev_status {
>>> */
>>> #define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1
>>>
>>> +/**
>>> + * struct devfreq_stats - Devfreq's transitions stats counters
>>> + * @freq_table: Optional list of frequencies to support statistics
>>> + * and freq_table must be generated in ascending order.
>>> + * @max_state: The size of freq_table.
>>> + * @total_trans: Number of devfreq transitions
>>> + * @trans_table: Statistics of devfreq transitions
>>> + * @time_in_state: Statistics of devfreq states
>>> + * @last_time: The last time stats were updated
>>> + * @stats_lock: Lock protecting trans_table, time_in_state,
>>> + * last_time and total_trans used for statistics
>>> + */
>>> +struct devfreq_stats {
>>> + unsigned long *freq_table;
>>> + unsigned int max_state;
>>> +
>>> + /* information for device frequency transition */
>>> + unsigned int total_trans;
>>> + unsigned int *trans_table;
>>> + u64 *time_in_state;
>>> + unsigned long long last_time;
>>> + spinlock_t stats_lock;
>>> +};
>>> +
>>> /**
>>> * struct devfreq_dev_profile - Devfreq's user device profile
>>> * @initial_freq: The operating frequency when devfreq_add_device() is
>>> @@ -88,15 +112,7 @@ struct devfreq_dev_status {
>>> * from devfreq_remove_device() call. If the user
>>> * has registered devfreq->nb at a notifier-head,
>>> * this is the time to unregister it.
>>> - * @freq_table: Optional list of frequencies to support statistics
>>> - * and freq_table must be generated in ascending order.
>>> - * @max_state: The size of freq_table.
>>> - * @total_trans: Number of devfreq transitions
>>> - * @trans_table: Statistics of devfreq transitions
>>> - * @time_in_state: Statistics of devfreq states
>>> - * @last_time: The last time stats were updated
>>> - * @stats_lock: Lock protecting trans_table, time_in_state,
>>> - * last_time and total_trans used for statistics
>>> + * @stats: Statistics of devfreq states and state transitions
>>> */
>>> struct devfreq_dev_profile {
>>> unsigned long initial_freq;
>>> @@ -108,14 +124,7 @@ struct devfreq_dev_profile {
>>> int (*get_cur_freq)(struct device *dev, unsigned long *freq);
>>> void (*exit)(struct device *dev);
>>>
>>> - unsigned long *freq_table;
>>> - unsigned int max_state;
>>> - /* information for device frequency transition */
>>> - unsigned int total_trans;
>>> - unsigned int *trans_table;
>>> - u64 *time_in_state;
>>> - unsigned long long last_time;
>>> - spinlock_t stats_lock;
>>> + struct devfreq_stats *stats;
>>> };
>>>
>>> /**
>>>
>
>


--
Best Regards,
Chanwoo Choi
Samsung Electronics

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