Thread (18 messages) 18 messages, 2 authors, 2017-10-18

Re: [PATCH v4 3/8] PM / devfreq: Use the available min/max frequency

From: MyungJoo Ham <myungjoo.ham@samsung.com>
Date: 2017-10-17 14:43:19
Also in: lkml

On Fri, Oct 13, 2017 at 4:48 PM, Chanwoo Choi [off-list ref] wrote:
quoted hunk ↗ jump to hunk
The commit a76caf55e5b35 ("thermal: Add devfreq cooling") is able
to disable OPP as a cooling device. In result, both update_devfreq()
and {min|max}_freq_show() have to consider the 'opp->available'
status of each OPP.

So, this patch adds the 'scaling_{min|max}_freq' to struct devfreq
in order to indicate the available mininum and maximum frequency
by adjusting OPP interface such as dev_pm_opp_{disable|enable}().
The 'scaling_{min|max}_freq' are used for on both update_devfreq()
and {min|max}_freq_show().

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq.c | 36 ++++++++++++++++++++++++++++--------
 include/linux/devfreq.h   |  4 ++++
 2 files changed, 32 insertions(+), 8 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index b6ba24e5db0d..9de013ffeb67 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
[]
quoted hunk ↗ jump to hunk
@@ -494,6 +499,19 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
        int ret;

        mutex_lock(&devfreq->lock);
+
+       devfreq->scaling_min_freq = find_available_min_freq(devfreq);
+       if (!devfreq->scaling_min_freq) {
+               mutex_unlock(&devfreq->lock);
+               return -EINVAL;
+       }
+
+       devfreq->scaling_max_freq = find_available_max_freq(devfreq);
+       if (!devfreq->max_freq) {
1. s/max_freq/scaling/max_freq/ ??

2. what if thermal is not active or has never triggered any event and
the user has never stated max/min? (making scaling_*_freq zero)
+               mutex_unlock(&devfreq->lock);
+               return -EINVAL;
+       }
+
        ret = update_devfreq(devfreq);
        mutex_unlock(&devfreq->lock);


-- 
MyungJoo Ham, Ph.D.
S/W Center, Samsung Electronics
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