| Message ID | 20220614230950.426-1-ansuelsmth@gmail.com |
|---|---|
| Headers | show |
| Series | PM / devfreq: Various Fixes to cpufreq based passive governor | expand |
On 22. 6. 15. 18:13, Ansuel Smith wrote: > On Wed, Jun 15, 2022 at 03:48:03PM +0900, Chanwoo Choi wrote: >> On 22. 6. 15. 08:09, Christian 'Ansuel' Marangi wrote: >>> With the passive governor, the cpu based scaling can PROBE_DEFER due to >>> the fact that CPU policy are not ready. >>> The cpufreq passive unregister notifier is called both from the >>> GOV_START errors and for the GOV_STOP and assume the notifier is >>> successfully registred every time. With GOV_START failing it's wrong to >>> loop over each possible CPU since the register path has failed for >>> some CPU policy not ready. Change the logic and unregister the notifer >>> based on the current allocated parent_cpu_data list to correctly handle >>> errors and the governor unregister path.>>> >>> Fixes: a03dacb0316f ("PM / devfreq: Add cpu based scaling support to passive governor") >>> Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com> >>> --- >>> drivers/devfreq/governor_passive.c | 39 +++++++++++++----------------- >>> 1 file changed, 17 insertions(+), 22 deletions(-) >>> >>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c >>> index 72c67979ebe1..95de336f20d5 100644 >>> --- a/drivers/devfreq/governor_passive.c >>> +++ b/drivers/devfreq/governor_passive.c >>> @@ -34,6 +34,20 @@ get_parent_cpu_data(struct devfreq_passive_data *p_data, >>> return NULL; >>> } >>> >>> +static void delete_parent_cpu_data(struct devfreq_passive_data *p_data) >>> +{ >>> + struct devfreq_cpu_data *parent_cpu_data, *tmp; >>> + >> >> Need to add the validation checking of argument as following: >> >> if (!p_data) >> return; >> > > Considering this is called only by cpufreq_passive_unregister_notifier > and cpufreq_passive_unregister_notifier is called only by devfreq_passive_event_handler > where the check is already done, isn't that redundant. > We should never reach delete_parent_cpu_data with no p_data. > (Unless you want to use that function somewhere else) Actually, right as you mentioned. I'd like to check the parameter validation on each function. But, I agree to keep this path without checking p_data. If needed on later, I'll do that. Applied it. Thanks. > >>> + list_for_each_entry_safe(parent_cpu_data, tmp, &p_data->cpu_data_list, node) { >>> + list_del(&parent_cpu_data->node); >>> + >>> + if (parent_cpu_data->opp_table) >>> + dev_pm_opp_put_opp_table(parent_cpu_data->opp_table); >>> + >>> + kfree(parent_cpu_data); >>> + } >>> +} >>> + >>> static unsigned long get_target_freq_by_required_opp(struct device *p_dev, >>> struct opp_table *p_opp_table, >>> struct opp_table *opp_table, >>> @@ -222,8 +236,7 @@ static int cpufreq_passive_unregister_notifier(struct devfreq *devfreq) >>> { >>> struct devfreq_passive_data *p_data >>> = (struct devfreq_passive_data *)devfreq->data; >>> - struct devfreq_cpu_data *parent_cpu_data; >>> - int cpu, ret = 0; >>> + int ret; >>> >>> if (p_data->nb.notifier_call) { >>> ret = cpufreq_unregister_notifier(&p_data->nb, >>> @@ -232,27 +245,9 @@ static int cpufreq_passive_unregister_notifier(struct devfreq *devfreq) >>> return ret; >>> } >>> >>> - for_each_possible_cpu(cpu) { >>> - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); >>> - if (!policy) { >>> - ret = -EINVAL; >>> - continue; >>> - } >>> - >>> - parent_cpu_data = get_parent_cpu_data(p_data, policy); >>> - if (!parent_cpu_data) { >>> - cpufreq_cpu_put(policy); >>> - continue; >>> - } >>> - >>> - list_del(&parent_cpu_data->node); >>> - if (parent_cpu_data->opp_table) >>> - dev_pm_opp_put_opp_table(parent_cpu_data->opp_table); >>> - kfree(parent_cpu_data); >>> - cpufreq_cpu_put(policy); >>> - } >>> + delete_parent_cpu_data(p_data); >>> >>> - return ret; >>> + return 0; >>> } >>> >>> static int cpufreq_passive_register_notifier(struct devfreq *devfreq) >> >> >> -- >> Best Regards, >> Samsung Electronics >> Chanwoo Choi >
Hi,
Thanks for the good catch.
I think that this patch fixes issue of commit 0ec09ac2cebe
("PM / devfreq: Set the freq_table of devfreq device").
When some devfreq driver without using passive governor
faces on the all errors including PROBE_DEFER
after executing devfreq_add_device, this issue will happen.
Also need to check the devfreq device driver using freq_table
which was allocated dynamically. In case of devfreq/drivers/exynos-bus.c
used the devfreq->profile->freq_table after devfreq_add_device.
On 22. 6. 15. 08:09, Christian 'Ansuel' Marangi wrote:
> Currently we reference the freq_table to the profile defined one and we
> make changes on it. Devfreq never supported PROBE_DEFER before the cpu
> based scaling support to the passive governor and assumed that a devfreq
> device could only had error and be done with it.
> Now that a device can PROBE_DEFER a rework to the freq_table logic is
> required.
>
> If a device PROBE_DEFER on the GOV_START, the freq_table is already set
> in the device profile struct and its init is skipped. This is due to the
> fact that it's common for devs to declare this kind of struct static.
> This cause the devfreq logic to find a freq table declared (freq_table
> not NULL) with random data and poiting to the old addrs freed by devm.
> This problem CAN be solved by devs by clearing the freq_table in their
> profile struct on driver exit path but it should not be trusted and it
> looks to use a flawed logic.
>
> A better solution is to move the freq_table and max_state to the
> devfreq struct and never change the profile struct.
> This permit to correctly handle PROBE_DEFER since the devfreq struct is
> reallocated and contains new values.
> Also the profile struct should only be used to init the driver and should
> not be used by the devfreq to write the freq_table if it's not provided
> by the driver.
>
If possible, could you explain the patch description more simply?
Maybe, just focus on the 'freq_table' issue by device managed functions (devs).
> Fixes: a03dacb0316f ("PM / devfreq: Add cpu based scaling support to passive governor")
> Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
> ---
> drivers/devfreq/devfreq.c | 71 ++++++++++++++----------------
> drivers/devfreq/governor_passive.c | 14 +++---
> include/linux/devfreq.h | 4 ++
> 3 files changed, 45 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 01474daf4548..2e2b3b414d67 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -123,7 +123,7 @@ void devfreq_get_freq_range(struct devfreq *devfreq,
> unsigned long *min_freq,
> unsigned long *max_freq)
> {
> - unsigned long *freq_table = devfreq->profile->freq_table;
> + unsigned long *freq_table = devfreq->freq_table;
> s32 qos_min_freq, qos_max_freq;
>
> lockdep_assert_held(&devfreq->lock);
> @@ -133,11 +133,11 @@ void devfreq_get_freq_range(struct devfreq *devfreq,
> * The devfreq drivers can initialize this in either ascending or
> * descending order and devfreq core supports both.
> */
> - if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) {
> + if (freq_table[0] < freq_table[devfreq->max_state - 1]) {
> *min_freq = freq_table[0];
> - *max_freq = freq_table[devfreq->profile->max_state - 1];
> + *max_freq = freq_table[devfreq->max_state - 1];
> } else {
> - *min_freq = freq_table[devfreq->profile->max_state - 1];
> + *min_freq = freq_table[devfreq->max_state - 1];
> *max_freq = freq_table[0];
> }
>
> @@ -169,8 +169,8 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
> {
> int lev;
>
> - for (lev = 0; lev < devfreq->profile->max_state; lev++)
> - if (freq == devfreq->profile->freq_table[lev])
> + for (lev = 0; lev < devfreq->max_state; lev++)
> + if (freq == devfreq->freq_table[lev])
> return lev;
>
> return -EINVAL;
> @@ -178,7 +178,6 @@ 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 dev_pm_opp *opp;
> unsigned long freq;
> int i, count;
> @@ -188,25 +187,22 @@ static int set_freq_table(struct devfreq *devfreq)
> if (count <= 0)
> return -EINVAL;
>
> - profile->max_state = count;
> - profile->freq_table = devm_kcalloc(devfreq->dev.parent,
> - profile->max_state,
> - sizeof(*profile->freq_table),
> - GFP_KERNEL);
> - if (!profile->freq_table) {
> - profile->max_state = 0;
> + devfreq->max_state = count;
> + devfreq->freq_table = devm_kcalloc(devfreq->dev.parent,
> + devfreq->max_state,
> + sizeof(*devfreq->freq_table),
> + GFP_KERNEL);
> + if (!devfreq->freq_table)
> return -ENOMEM;
> - }
>
> - for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
> + for (i = 0, freq = 0; i < devfreq->max_state; 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;
> + devm_kfree(devfreq->dev.parent, devfreq->freq_table);
> return PTR_ERR(opp);
> }
> dev_pm_opp_put(opp);
> - profile->freq_table[i] = freq;
> + devfreq->freq_table[i] = freq;
> }
>
> return 0;
> @@ -246,7 +242,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
>
> if (lev != prev_lev) {
> devfreq->stats.trans_table[
> - (prev_lev * devfreq->profile->max_state) + lev]++;
> + (prev_lev * devfreq->max_state) + lev]++;
> devfreq->stats.total_trans++;
> }
>
> @@ -835,6 +831,9 @@ struct devfreq *devfreq_add_device(struct device *dev,
> if (err < 0)
> goto err_dev;
> mutex_lock(&devfreq->lock);
> + } else {
> + devfreq->freq_table = devfreq->profile->freq_table;
> + devfreq->max_state = devfreq->profile->max_state;
> }
>
> devfreq->scaling_min_freq = find_available_min_freq(devfreq);
> @@ -870,8 +869,8 @@ struct devfreq *devfreq_add_device(struct device *dev,
>
> devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
> array3_size(sizeof(unsigned int),
> - devfreq->profile->max_state,
> - devfreq->profile->max_state),
> + devfreq->max_state,
> + devfreq->max_state),
> GFP_KERNEL);
> if (!devfreq->stats.trans_table) {
> mutex_unlock(&devfreq->lock);
> @@ -880,7 +879,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> }
>
> devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
> - devfreq->profile->max_state,
> + devfreq->max_state,
> sizeof(*devfreq->stats.time_in_state),
> GFP_KERNEL);
> if (!devfreq->stats.time_in_state) {
> @@ -1665,9 +1664,9 @@ static ssize_t available_frequencies_show(struct device *d,
>
> mutex_lock(&df->lock);
>
> - for (i = 0; i < df->profile->max_state; i++)
> + for (i = 0; i < df->max_state; i++)
> count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
> - "%lu ", df->profile->freq_table[i]);
> + "%lu ", df->freq_table[i]);
>
> mutex_unlock(&df->lock);
> /* Truncate the trailing space */
> @@ -1690,7 +1689,7 @@ static ssize_t trans_stat_show(struct device *dev,
>
> if (!df->profile)
> return -EINVAL;
> - max_state = df->profile->max_state;
> + max_state = df->max_state;
>
> if (max_state == 0)
> return sprintf(buf, "Not Supported.\n");
> @@ -1707,19 +1706,17 @@ static ssize_t trans_stat_show(struct device *dev,
> len += sprintf(buf + len, " :");
> for (i = 0; i < max_state; i++)
> len += sprintf(buf + len, "%10lu",
> - df->profile->freq_table[i]);
> + df->freq_table[i]);
>
> len += sprintf(buf + len, " time(ms)\n");
>
> for (i = 0; i < max_state; i++) {
> - if (df->profile->freq_table[i]
> - == df->previous_freq) {
> + if (df->freq_table[i] == df->previous_freq)
> len += sprintf(buf + len, "*");
> - } else {
> + else
> len += sprintf(buf + len, " ");
> - }
> - len += sprintf(buf + len, "%10lu:",
> - df->profile->freq_table[i]);
> +
> + len += sprintf(buf + len, "%10lu:", df->freq_table[i]);
> for (j = 0; j < max_state; j++)
> len += sprintf(buf + len, "%10u",
> df->stats.trans_table[(i * max_state) + j]);
> @@ -1743,7 +1740,7 @@ static ssize_t trans_stat_store(struct device *dev,
> if (!df->profile)
> return -EINVAL;
>
> - if (df->profile->max_state == 0)
> + if (df->max_state == 0)
> return count;
>
> err = kstrtoint(buf, 10, &value);
> @@ -1751,11 +1748,11 @@ static ssize_t trans_stat_store(struct device *dev,
> return -EINVAL;
>
> mutex_lock(&df->lock);
> - memset(df->stats.time_in_state, 0, (df->profile->max_state *
> + memset(df->stats.time_in_state, 0, (df->max_state *
> sizeof(*df->stats.time_in_state)));
> memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
> - df->profile->max_state,
> - df->profile->max_state));
> + df->max_state,
> + df->max_state));
> df->stats.total_trans = 0;
> df->stats.last_update = get_jiffies_64();
> mutex_unlock(&df->lock);
> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> index dcc9dd518197..1810966fd61d 100644
> --- a/drivers/devfreq/governor_passive.c
> +++ b/drivers/devfreq/governor_passive.c
> @@ -145,18 +145,18 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq,
> goto out;
>
> /* Use interpolation if required opps is not available */
> - for (i = 0; i < parent_devfreq->profile->max_state; i++)
> - if (parent_devfreq->profile->freq_table[i] == *freq)
> + for (i = 0; i < parent_devfreq->max_state; i++)
> + if (parent_devfreq->freq_table[i] == *freq)
> break;
>
> - if (i == parent_devfreq->profile->max_state)
> + if (i == parent_devfreq->max_state)
> return -EINVAL;
>
> - if (i < devfreq->profile->max_state) {
> - child_freq = devfreq->profile->freq_table[i];
> + if (i < devfreq->max_state) {
> + child_freq = devfreq->freq_table[i];
> } else {
> - count = devfreq->profile->max_state;
> - child_freq = devfreq->profile->freq_table[count - 1];
> + count = devfreq->max_state;
> + child_freq = devfreq->freq_table[count - 1];
> }
>
> out:
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index dc10bee75a72..770a7532655c 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -185,6 +185,10 @@ struct devfreq {
> struct notifier_block nb;
> struct delayed_work work;
>
> + /* devfreq local freq_table */
> + unsigned long *freq_table;
> + unsigned int max_state;
> +
> unsigned long previous_freq;
> struct devfreq_dev_status last_status;
>
On Sat, Jun 18, 2022 at 04:33:19AM +0900, Chanwoo Choi wrote: > Hi, > > Thanks for the good catch. > > > I think that this patch fixes issue of commit 0ec09ac2cebe > ("PM / devfreq: Set the freq_table of devfreq device"). > Should I add this to the Fixes list? > When some devfreq driver without using passive governor > faces on the all errors including PROBE_DEFER > after executing devfreq_add_device, this issue will happen. > > Also need to check the devfreq device driver using freq_table > which was allocated dynamically. In case of devfreq/drivers/exynos-bus.c > used the devfreq->profile->freq_table after devfreq_add_device. > > On 22. 6. 15. 08:09, Christian 'Ansuel' Marangi wrote: > > Currently we reference the freq_table to the profile defined one and we > > make changes on it. Devfreq never supported PROBE_DEFER before the cpu > > based scaling support to the passive governor and assumed that a devfreq > > device could only had error and be done with it. > > Now that a device can PROBE_DEFER a rework to the freq_table logic is > > required. > > > > If a device PROBE_DEFER on the GOV_START, the freq_table is already set > > in the device profile struct and its init is skipped. This is due to the > > fact that it's common for devs to declare this kind of struct static. > > This cause the devfreq logic to find a freq table declared (freq_table > > not NULL) with random data and poiting to the old addrs freed by devm. > > This problem CAN be solved by devs by clearing the freq_table in their > > profile struct on driver exit path but it should not be trusted and it > > looks to use a flawed logic. > > > > A better solution is to move the freq_table and max_state to the > > devfreq struct and never change the profile struct. > > This permit to correctly handle PROBE_DEFER since the devfreq struct is > > reallocated and contains new values. > > Also the profile struct should only be used to init the driver and should > > not be used by the devfreq to write the freq_table if it's not provided > > by the driver. > > > > If possible, could you explain the patch description more simply? > Maybe, just focus on the 'freq_table' issue by device managed functions (devs). > Sure! > > > Fixes: a03dacb0316f ("PM / devfreq: Add cpu based scaling support to passive governor") > > Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com> > > --- > > drivers/devfreq/devfreq.c | 71 ++++++++++++++---------------- > > drivers/devfreq/governor_passive.c | 14 +++--- > > include/linux/devfreq.h | 4 ++ > > 3 files changed, 45 insertions(+), 44 deletions(-) > > > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > > index 01474daf4548..2e2b3b414d67 100644 > > --- a/drivers/devfreq/devfreq.c > > +++ b/drivers/devfreq/devfreq.c > > @@ -123,7 +123,7 @@ void devfreq_get_freq_range(struct devfreq *devfreq, > > unsigned long *min_freq, > > unsigned long *max_freq) > > { > > - unsigned long *freq_table = devfreq->profile->freq_table; > > + unsigned long *freq_table = devfreq->freq_table; > > s32 qos_min_freq, qos_max_freq; > > > > lockdep_assert_held(&devfreq->lock); > > @@ -133,11 +133,11 @@ void devfreq_get_freq_range(struct devfreq *devfreq, > > * The devfreq drivers can initialize this in either ascending or > > * descending order and devfreq core supports both. > > */ > > - if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { > > + if (freq_table[0] < freq_table[devfreq->max_state - 1]) { > > *min_freq = freq_table[0]; > > - *max_freq = freq_table[devfreq->profile->max_state - 1]; > > + *max_freq = freq_table[devfreq->max_state - 1]; > > } else { > > - *min_freq = freq_table[devfreq->profile->max_state - 1]; > > + *min_freq = freq_table[devfreq->max_state - 1]; > > *max_freq = freq_table[0]; > > } > > > > @@ -169,8 +169,8 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq) > > { > > int lev; > > > > - for (lev = 0; lev < devfreq->profile->max_state; lev++) > > - if (freq == devfreq->profile->freq_table[lev]) > > + for (lev = 0; lev < devfreq->max_state; lev++) > > + if (freq == devfreq->freq_table[lev]) > > return lev; > > > > return -EINVAL; > > @@ -178,7 +178,6 @@ 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 dev_pm_opp *opp; > > unsigned long freq; > > int i, count; > > @@ -188,25 +187,22 @@ static int set_freq_table(struct devfreq *devfreq) > > if (count <= 0) > > return -EINVAL; > > > > - profile->max_state = count; > > - profile->freq_table = devm_kcalloc(devfreq->dev.parent, > > - profile->max_state, > > - sizeof(*profile->freq_table), > > - GFP_KERNEL); > > - if (!profile->freq_table) { > > - profile->max_state = 0; > > + devfreq->max_state = count; > > + devfreq->freq_table = devm_kcalloc(devfreq->dev.parent, > > + devfreq->max_state, > > + sizeof(*devfreq->freq_table), > > + GFP_KERNEL); > > + if (!devfreq->freq_table) > > return -ENOMEM; > > - } > > > > - for (i = 0, freq = 0; i < profile->max_state; i++, freq++) { > > + for (i = 0, freq = 0; i < devfreq->max_state; 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; > > + devm_kfree(devfreq->dev.parent, devfreq->freq_table); > > return PTR_ERR(opp); > > } > > dev_pm_opp_put(opp); > > - profile->freq_table[i] = freq; > > + devfreq->freq_table[i] = freq; > > } > > > > return 0; > > @@ -246,7 +242,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) > > > > if (lev != prev_lev) { > > devfreq->stats.trans_table[ > > - (prev_lev * devfreq->profile->max_state) + lev]++; > > + (prev_lev * devfreq->max_state) + lev]++; > > devfreq->stats.total_trans++; > > } > > > > @@ -835,6 +831,9 @@ struct devfreq *devfreq_add_device(struct device *dev, > > if (err < 0) > > goto err_dev; > > mutex_lock(&devfreq->lock); > > + } else { > > + devfreq->freq_table = devfreq->profile->freq_table; > > + devfreq->max_state = devfreq->profile->max_state; > > } > > > > devfreq->scaling_min_freq = find_available_min_freq(devfreq); > > @@ -870,8 +869,8 @@ struct devfreq *devfreq_add_device(struct device *dev, > > > > devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev, > > array3_size(sizeof(unsigned int), > > - devfreq->profile->max_state, > > - devfreq->profile->max_state), > > + devfreq->max_state, > > + devfreq->max_state), > > GFP_KERNEL); > > if (!devfreq->stats.trans_table) { > > mutex_unlock(&devfreq->lock); > > @@ -880,7 +879,7 @@ struct devfreq *devfreq_add_device(struct device *dev, > > } > > > > devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev, > > - devfreq->profile->max_state, > > + devfreq->max_state, > > sizeof(*devfreq->stats.time_in_state), > > GFP_KERNEL); > > if (!devfreq->stats.time_in_state) { > > @@ -1665,9 +1664,9 @@ static ssize_t available_frequencies_show(struct device *d, > > > > mutex_lock(&df->lock); > > > > - for (i = 0; i < df->profile->max_state; i++) > > + for (i = 0; i < df->max_state; i++) > > count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), > > - "%lu ", df->profile->freq_table[i]); > > + "%lu ", df->freq_table[i]); > > > > mutex_unlock(&df->lock); > > /* Truncate the trailing space */ > > @@ -1690,7 +1689,7 @@ static ssize_t trans_stat_show(struct device *dev, > > > > if (!df->profile) > > return -EINVAL; > > - max_state = df->profile->max_state; > > + max_state = df->max_state; > > > > if (max_state == 0) > > return sprintf(buf, "Not Supported.\n"); > > @@ -1707,19 +1706,17 @@ static ssize_t trans_stat_show(struct device *dev, > > len += sprintf(buf + len, " :"); > > for (i = 0; i < max_state; i++) > > len += sprintf(buf + len, "%10lu", > > - df->profile->freq_table[i]); > > + df->freq_table[i]); > > > > len += sprintf(buf + len, " time(ms)\n"); > > > > for (i = 0; i < max_state; i++) { > > - if (df->profile->freq_table[i] > > - == df->previous_freq) { > > + if (df->freq_table[i] == df->previous_freq) > > len += sprintf(buf + len, "*"); > > - } else { > > + else > > len += sprintf(buf + len, " "); > > - } > > - len += sprintf(buf + len, "%10lu:", > > - df->profile->freq_table[i]); > > + > > + len += sprintf(buf + len, "%10lu:", df->freq_table[i]); > > for (j = 0; j < max_state; j++) > > len += sprintf(buf + len, "%10u", > > df->stats.trans_table[(i * max_state) + j]); > > @@ -1743,7 +1740,7 @@ static ssize_t trans_stat_store(struct device *dev, > > if (!df->profile) > > return -EINVAL; > > > > - if (df->profile->max_state == 0) > > + if (df->max_state == 0) > > return count; > > > > err = kstrtoint(buf, 10, &value); > > @@ -1751,11 +1748,11 @@ static ssize_t trans_stat_store(struct device *dev, > > return -EINVAL; > > > > mutex_lock(&df->lock); > > - memset(df->stats.time_in_state, 0, (df->profile->max_state * > > + memset(df->stats.time_in_state, 0, (df->max_state * > > sizeof(*df->stats.time_in_state))); > > memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int), > > - df->profile->max_state, > > - df->profile->max_state)); > > + df->max_state, > > + df->max_state)); > > df->stats.total_trans = 0; > > df->stats.last_update = get_jiffies_64(); > > mutex_unlock(&df->lock); > > diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c > > index dcc9dd518197..1810966fd61d 100644 > > --- a/drivers/devfreq/governor_passive.c > > +++ b/drivers/devfreq/governor_passive.c > > @@ -145,18 +145,18 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq, > > goto out; > > > > /* Use interpolation if required opps is not available */ > > - for (i = 0; i < parent_devfreq->profile->max_state; i++) > > - if (parent_devfreq->profile->freq_table[i] == *freq) > > + for (i = 0; i < parent_devfreq->max_state; i++) > > + if (parent_devfreq->freq_table[i] == *freq) > > break; > > > > - if (i == parent_devfreq->profile->max_state) > > + if (i == parent_devfreq->max_state) > > return -EINVAL; > > > > - if (i < devfreq->profile->max_state) { > > - child_freq = devfreq->profile->freq_table[i]; > > + if (i < devfreq->max_state) { > > + child_freq = devfreq->freq_table[i]; > > } else { > > - count = devfreq->profile->max_state; > > - child_freq = devfreq->profile->freq_table[count - 1]; > > + count = devfreq->max_state; > > + child_freq = devfreq->freq_table[count - 1]; > > } > > > > out: > > diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h > > index dc10bee75a72..770a7532655c 100644 > > --- a/include/linux/devfreq.h > > +++ b/include/linux/devfreq.h > > @@ -185,6 +185,10 @@ struct devfreq { > > struct notifier_block nb; > > struct delayed_work work; > > > > + /* devfreq local freq_table */ > > + unsigned long *freq_table; > > + unsigned int max_state; > > + > > unsigned long previous_freq; > > struct devfreq_dev_status last_status; > > > > > -- > Best Regards, > Samsung Electronics > Chanwoo Choi
On 22. 6. 18. 04:38, Christian Marangi wrote: > On Sat, Jun 18, 2022 at 04:33:19AM +0900, Chanwoo Choi wrote: >> Hi, >> >> Thanks for the good catch. >> >> >> I think that this patch fixes issue of commit 0ec09ac2cebe >> ("PM / devfreq: Set the freq_table of devfreq device"). >> > > Should I add this to the Fixes list? Replace fixes commit information with commit 0ec09ac2cebe. I'd like you to make the patch separated from this series and then send them to linux-stable mailling list tool because I think this patch should be maintained by linux stable patches. > >> When some devfreq driver without using passive governor >> faces on the all errors including PROBE_DEFER >> after executing devfreq_add_device, this issue will happen. >> >> Also need to check the devfreq device driver using freq_table >> which was allocated dynamically. In case of devfreq/drivers/exynos-bus.c >> used the devfreq->profile->freq_table after devfreq_add_device. >> >> On 22. 6. 15. 08:09, Christian 'Ansuel' Marangi wrote: >>> Currently we reference the freq_table to the profile defined one and we >>> make changes on it. Devfreq never supported PROBE_DEFER before the cpu >>> based scaling support to the passive governor and assumed that a devfreq >>> device could only had error and be done with it. >>> Now that a device can PROBE_DEFER a rework to the freq_table logic is >>> required. >>> >>> If a device PROBE_DEFER on the GOV_START, the freq_table is already set >>> in the device profile struct and its init is skipped. This is due to the >>> fact that it's common for devs to declare this kind of struct static. >>> This cause the devfreq logic to find a freq table declared (freq_table >>> not NULL) with random data and poiting to the old addrs freed by devm. >> > This problem CAN be solved by devs by clearing the freq_table in their >>> profile struct on driver exit path but it should not be trusted and it >>> looks to use a flawed logic. >>> >>> A better solution is to move the freq_table and max_state to the >>> devfreq struct and never change the profile struct. >>> This permit to correctly handle PROBE_DEFER since the devfreq struct is >>> reallocated and contains new values. >>> Also the profile struct should only be used to init the driver and should >>> not be used by the devfreq to write the freq_table if it's not provided >>> by the driver. >>> >> >> If possible, could you explain the patch description more simply? >> Maybe, just focus on the 'freq_table' issue by device managed functions (devs). >> > > Sure! Thanks. > >> >>> Fixes: a03dacb0316f ("PM / devfreq: Add cpu based scaling support to passive governor") >>> Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com> >>> --- >>> drivers/devfreq/devfreq.c | 71 ++++++++++++++---------------- >>> drivers/devfreq/governor_passive.c | 14 +++--- >>> include/linux/devfreq.h | 4 ++ >>> 3 files changed, 45 insertions(+), 44 deletions(-) >>> >>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >>> index 01474daf4548..2e2b3b414d67 100644 >>> --- a/drivers/devfreq/devfreq.c >>> +++ b/drivers/devfreq/devfreq.c >>> @@ -123,7 +123,7 @@ void devfreq_get_freq_range(struct devfreq *devfreq, >>> unsigned long *min_freq, >>> unsigned long *max_freq) >>> { >>> - unsigned long *freq_table = devfreq->profile->freq_table; >>> + unsigned long *freq_table = devfreq->freq_table; >>> s32 qos_min_freq, qos_max_freq; >>> >>> lockdep_assert_held(&devfreq->lock); >>> @@ -133,11 +133,11 @@ void devfreq_get_freq_range(struct devfreq *devfreq, >>> * The devfreq drivers can initialize this in either ascending or >>> * descending order and devfreq core supports both. >>> */ >>> - if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { >>> + if (freq_table[0] < freq_table[devfreq->max_state - 1]) { >>> *min_freq = freq_table[0]; >>> - *max_freq = freq_table[devfreq->profile->max_state - 1]; >>> + *max_freq = freq_table[devfreq->max_state - 1]; >>> } else { >>> - *min_freq = freq_table[devfreq->profile->max_state - 1]; >>> + *min_freq = freq_table[devfreq->max_state - 1]; >>> *max_freq = freq_table[0]; >>> } >>> >>> @@ -169,8 +169,8 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq) >>> { >>> int lev; >>> >>> - for (lev = 0; lev < devfreq->profile->max_state; lev++) >>> - if (freq == devfreq->profile->freq_table[lev]) >>> + for (lev = 0; lev < devfreq->max_state; lev++) >>> + if (freq == devfreq->freq_table[lev]) >>> return lev; >>> >>> return -EINVAL; >>> @@ -178,7 +178,6 @@ 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 dev_pm_opp *opp; >>> unsigned long freq; >>> int i, count; >>> @@ -188,25 +187,22 @@ static int set_freq_table(struct devfreq *devfreq) >>> if (count <= 0) >>> return -EINVAL; >>> >>> - profile->max_state = count; >>> - profile->freq_table = devm_kcalloc(devfreq->dev.parent, >>> - profile->max_state, >>> - sizeof(*profile->freq_table), >>> - GFP_KERNEL); >>> - if (!profile->freq_table) { >>> - profile->max_state = 0; >>> + devfreq->max_state = count; >>> + devfreq->freq_table = devm_kcalloc(devfreq->dev.parent, >>> + devfreq->max_state, >>> + sizeof(*devfreq->freq_table), >>> + GFP_KERNEL); >>> + if (!devfreq->freq_table) >>> return -ENOMEM; >>> - } >>> >>> - for (i = 0, freq = 0; i < profile->max_state; i++, freq++) { >>> + for (i = 0, freq = 0; i < devfreq->max_state; 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; >>> + devm_kfree(devfreq->dev.parent, devfreq->freq_table); >>> return PTR_ERR(opp); >>> } >>> dev_pm_opp_put(opp); >>> - profile->freq_table[i] = freq; >>> + devfreq->freq_table[i] = freq; >>> } >>> >>> return 0; >>> @@ -246,7 +242,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) >>> >>> if (lev != prev_lev) { >>> devfreq->stats.trans_table[ >>> - (prev_lev * devfreq->profile->max_state) + lev]++; >>> + (prev_lev * devfreq->max_state) + lev]++; >>> devfreq->stats.total_trans++; >>> } >>> >>> @@ -835,6 +831,9 @@ struct devfreq *devfreq_add_device(struct device *dev, >>> if (err < 0) >>> goto err_dev; >>> mutex_lock(&devfreq->lock); >>> + } else { >>> + devfreq->freq_table = devfreq->profile->freq_table; >>> + devfreq->max_state = devfreq->profile->max_state; >>> } >>> >>> devfreq->scaling_min_freq = find_available_min_freq(devfreq); >>> @@ -870,8 +869,8 @@ struct devfreq *devfreq_add_device(struct device *dev, >>> >>> devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev, >>> array3_size(sizeof(unsigned int), >>> - devfreq->profile->max_state, >>> - devfreq->profile->max_state), >>> + devfreq->max_state, >>> + devfreq->max_state), >>> GFP_KERNEL); >>> if (!devfreq->stats.trans_table) { >>> mutex_unlock(&devfreq->lock); >>> @@ -880,7 +879,7 @@ struct devfreq *devfreq_add_device(struct device *dev, >>> } >>> >>> devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev, >>> - devfreq->profile->max_state, >>> + devfreq->max_state, >>> sizeof(*devfreq->stats.time_in_state), >>> GFP_KERNEL); >>> if (!devfreq->stats.time_in_state) { >>> @@ -1665,9 +1664,9 @@ static ssize_t available_frequencies_show(struct device *d, >>> >>> mutex_lock(&df->lock); >>> >>> - for (i = 0; i < df->profile->max_state; i++) >>> + for (i = 0; i < df->max_state; i++) >>> count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), >>> - "%lu ", df->profile->freq_table[i]); >>> + "%lu ", df->freq_table[i]); >>> >>> mutex_unlock(&df->lock); >>> /* Truncate the trailing space */ >>> @@ -1690,7 +1689,7 @@ static ssize_t trans_stat_show(struct device *dev, >>> >>> if (!df->profile) >>> return -EINVAL; >>> - max_state = df->profile->max_state; >>> + max_state = df->max_state; >>> >>> if (max_state == 0) >>> return sprintf(buf, "Not Supported.\n"); >>> @@ -1707,19 +1706,17 @@ static ssize_t trans_stat_show(struct device *dev, >>> len += sprintf(buf + len, " :"); >>> for (i = 0; i < max_state; i++) >>> len += sprintf(buf + len, "%10lu", >>> - df->profile->freq_table[i]); >>> + df->freq_table[i]); >>> >>> len += sprintf(buf + len, " time(ms)\n"); >>> >>> for (i = 0; i < max_state; i++) { >>> - if (df->profile->freq_table[i] >>> - == df->previous_freq) { >>> + if (df->freq_table[i] == df->previous_freq) >>> len += sprintf(buf + len, "*"); >>> - } else { >>> + else >>> len += sprintf(buf + len, " "); >>> - } >>> - len += sprintf(buf + len, "%10lu:", >>> - df->profile->freq_table[i]); >>> + >>> + len += sprintf(buf + len, "%10lu:", df->freq_table[i]); >>> for (j = 0; j < max_state; j++) >>> len += sprintf(buf + len, "%10u", >>> df->stats.trans_table[(i * max_state) + j]); >>> @@ -1743,7 +1740,7 @@ static ssize_t trans_stat_store(struct device *dev, >>> if (!df->profile) >>> return -EINVAL; >>> >>> - if (df->profile->max_state == 0) >>> + if (df->max_state == 0) >>> return count; >>> >>> err = kstrtoint(buf, 10, &value); >>> @@ -1751,11 +1748,11 @@ static ssize_t trans_stat_store(struct device *dev, >>> return -EINVAL; >>> >>> mutex_lock(&df->lock); >>> - memset(df->stats.time_in_state, 0, (df->profile->max_state * >>> + memset(df->stats.time_in_state, 0, (df->max_state * >>> sizeof(*df->stats.time_in_state))); >>> memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int), >>> - df->profile->max_state, >>> - df->profile->max_state)); >>> + df->max_state, >>> + df->max_state)); >>> df->stats.total_trans = 0; >>> df->stats.last_update = get_jiffies_64(); >>> mutex_unlock(&df->lock); >>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c >>> index dcc9dd518197..1810966fd61d 100644 >>> --- a/drivers/devfreq/governor_passive.c >>> +++ b/drivers/devfreq/governor_passive.c >>> @@ -145,18 +145,18 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq, >>> goto out; >>> >>> /* Use interpolation if required opps is not available */ >>> - for (i = 0; i < parent_devfreq->profile->max_state; i++) >>> - if (parent_devfreq->profile->freq_table[i] == *freq) >>> + for (i = 0; i < parent_devfreq->max_state; i++) >>> + if (parent_devfreq->freq_table[i] == *freq) >>> break; >>> >>> - if (i == parent_devfreq->profile->max_state) >>> + if (i == parent_devfreq->max_state) >>> return -EINVAL; >>> >>> - if (i < devfreq->profile->max_state) { >>> - child_freq = devfreq->profile->freq_table[i]; >>> + if (i < devfreq->max_state) { >>> + child_freq = devfreq->freq_table[i]; >>> } else { >>> - count = devfreq->profile->max_state; >>> - child_freq = devfreq->profile->freq_table[count - 1]; >>> + count = devfreq->max_state; >>> + child_freq = devfreq->freq_table[count - 1]; >>> } >>> >>> out: >>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h >>> index dc10bee75a72..770a7532655c 100644 >>> --- a/include/linux/devfreq.h >>> +++ b/include/linux/devfreq.h >>> @@ -185,6 +185,10 @@ struct devfreq { >>> struct notifier_block nb; >>> struct delayed_work work; >>> >>> + /* devfreq local freq_table */ This comment is not necessary. Please remove it. >>> + unsigned long *freq_table; >>> + unsigned int max_state; And need to add the description of newly added variables to 'struct devfreq' structure description. >>> + >>> unsigned long previous_freq; >>> struct devfreq_dev_status last_status; >>> >> >> >> -- >> Best Regards, >> Samsung Electronics >> Chanwoo Choi >