Messages in this thread Patch in this message | | | From | Chanwoo Choi <> | Subject | [PATCH 06/12] PM / devfreq: Check the entered min/max_freq is supported or not | Date | Thu, 24 Aug 2017 10:42:53 +0900 |
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The existing {min|max}_freq_store() only check the range of entered frequency. If the unsupported frequency is entered and the entered frequency is within the ranges, {min|max}_freq_store() will store it to devfreq->{min|max}_freq. And then when some user try to read the {min|max}_freq, the devfreq show the unsupported frequency value.
In order to fix this issue, this patch checks whether the entered frequency is supported or not by OPP interface.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> --- drivers/devfreq/devfreq.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 56f8a0473834..f10017fe400f 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -97,6 +97,25 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) return max_freq; } +static int is_supported_freq(struct devfreq *devfreq, unsigned long freq) +{ + struct device *dev = devfreq->dev.parent; + struct dev_pm_opp *opp; + int ret = 0; + + /* Check whether entered frequency is supported or not */ + opp = dev_pm_opp_find_freq_exact(dev, freq, true); + if (PTR_ERR(opp) == -ERANGE) + opp = dev_pm_opp_find_freq_exact(dev, freq, false); + + if (IS_ERR(opp)) + ret = PTR_ERR(opp); + + dev_pm_opp_put(opp); + + return ret; +} + /** * devfreq_get_freq_level() - Lookup freq_table for the frequency * @devfreq: the devfreq instance @@ -1099,9 +1118,8 @@ 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); - unsigned long value; + unsigned long value, max; int ret; - unsigned long max; ret = sscanf(buf, "%lu", &value); if (ret != 1) @@ -1114,6 +1132,11 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, goto unlock; } + /* Check whether entered frequency is supported or not */ + ret = is_supported_freq(df, value); + if (ret < 0) + goto unlock; + df->min_freq = value; update_devfreq(df); ret = count; @@ -1126,9 +1149,8 @@ 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); - unsigned long value; + unsigned long value, min; int ret; - unsigned long min; ret = sscanf(buf, "%lu", &value); if (ret != 1) @@ -1141,6 +1163,11 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, goto unlock; } + /* Check whether entered frequency is supported or not */ + ret = is_supported_freq(df, value); + if (ret < 0) + goto unlock; + df->max_freq = value; update_devfreq(df); ret = count; -- 1.9.1
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