From: MyungJoo Ham <myungjoo.ham@samsung.com>
Date: Mon, 23 Nov 2015 06:45:36 +0000 (+0900)
Subject: PM / devfreq: Do not show statistics if it's not ready.
X-Git-Tag: v4.5-rc1~37^2~2^2^2~2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=34bd322070a41898b032f59a0dfd345627fc1e7e;p=karo-tx-linux.git

PM / devfreq: Do not show statistics if it's not ready.

Before this patch for a device without statistics support,

$ cat trans_stat
    From  :   To
          :   time(ms)
Total transitions : 0
$

After this patch applied for such a device,

$ cat trans_stat
Not Supported.
$

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
---

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index d36fa2db4d29..984c5e9e7bdd 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1049,6 +1049,8 @@ static ssize_t trans_stat_show(struct device *dev,
 	if (!devfreq->stop_polling &&
 			devfreq_update_status(devfreq, devfreq->previous_freq))
 		return 0;
+	if (max_state == 0)
+		return sprintf(buf, "Not Supported.\n");
 
 	len = sprintf(buf, "     From  :   To\n");
 	len += sprintf(buf + len, "           :");