> The existing {min|max}_freq sysfs nodes don't consider whether min/max_freq
> are available or not. Those sysfs nodes show just the stored value
> in the struct devfreq.
>
> The devfreq uses the OPP interface and then dev_pm_opp_{disable|add}()
> might change the state of the device's supported frequency. This patch
> shows the available minimum and maximum frequency through sysfs node.
>
> Signed-off-by: Chanwoo Choi <[email protected]>
> ---
> drivers/devfreq/devfreq.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 2ce1fd0a1324..799a0cf75d39 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -1128,7 +1128,14 @@ static ssize_t min_freq_store(struct device *dev,
> struct device_attribute *attr,
> static ssize_t min_freq_show(struct device *dev, struct device_attribute
> *attr,
> char *buf)
> {
> - return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
> + struct devfreq *df = to_devfreq(dev);
> + unsigned long min_freq = to_devfreq(dev)->min_freq;
> + unsigned long available_min_freq = find_available_min_freq(df);
> +
> + if (available_min_freq != 0 && min_freq < available_min_freq)
nitpick:
If available_min_freq == 0,
it can't be min_freq < available_min_freq anyway;
it's unsigned.
> + min_freq = available_min_freq;
> +
> + return sprintf(buf, "%lu\n", min_freq);
> }
>
> static ssize_t max_freq_store(struct device *dev, struct device_attribute
> *attr,
> @@ -1162,7 +1169,14 @@ static ssize_t max_freq_store(struct device *dev,
> struct device_attribute *attr,
> static ssize_t max_freq_show(struct device *dev, struct device_attribute
> *attr,
> char *buf)
> {
> - return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
> + struct devfreq *df = to_devfreq(dev);
> + unsigned long max_freq = to_devfreq(dev)->max_freq;
> + unsigned long available_max_freq = find_available_max_freq(df);
> +
> + if (available_max_freq != 0 && max_freq > available_max_freq)
> + max_freq = available_max_freq;
similar here.
> +
> + return sprintf(buf, "%lu\n", max_freq);
> }
> static DEVICE_ATTR_RW(max_freq);
