From: Hanjun Guo <guohanjun@huawei.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Doug Smythies <dsmythies@telus.net>
Cc: <linux-pm@vger.kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Hanjun Guo <guohanjun@huawei.com>
Subject: [PATCH 2/6] cpuidle: sysfs: Accept governor name with 15 characters
Date: Tue, 19 May 2020 14:25:21 +0800 [thread overview]
Message-ID: <1589869525-29893-3-git-send-email-guohanjun@huawei.com> (raw)
In-Reply-To: <1589869525-29893-1-git-send-email-guohanjun@huawei.com>
CPUIDLE_NAME_LEN is 16, so it's possible to accept governor name
with 15 characters, but now store_current_governor() rejects
governor name with 15 characters as it returns -EINVAL if count
equals CPUIDLE_NAME_LEN.
Refactor the code to accept such case and simplify the code.
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
---
drivers/cpuidle/sysfs.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 477b05a..a57ad10 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -85,34 +85,25 @@ static ssize_t store_current_governor(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
- char gov_name[CPUIDLE_NAME_LEN];
- int ret = -EINVAL;
- size_t len = count;
+ char gov_name[CPUIDLE_NAME_LEN + 1];
+ int ret;
struct cpuidle_governor *gov;
- if (!len || len >= sizeof(gov_name))
+ ret = sscanf(buf, "%" __stringify(CPUIDLE_NAME_LEN) "s", gov_name);
+ if (ret != 1)
return -EINVAL;
- memcpy(gov_name, buf, len);
- gov_name[len] = '\0';
- if (gov_name[len - 1] == '\n')
- gov_name[--len] = '\0';
-
mutex_lock(&cpuidle_lock);
-
+ ret = -EINVAL;
list_for_each_entry(gov, &cpuidle_governors, governor_list) {
- if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
+ if (!strncmp(gov->name, gov_name, CPUIDLE_NAME_LEN)) {
ret = cpuidle_switch_governor(gov);
break;
}
}
-
mutex_unlock(&cpuidle_lock);
- if (ret)
- return ret;
- else
- return count;
+ return ret ? ret : count;
}
static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
--
1.7.12.4
next prev parent reply other threads:[~2020-05-19 6:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 6:25 [PATCH 0/6] cpuidle: Make cpuidle governor switchable to be the default behaviour Hanjun Guo
2020-05-19 6:25 ` [PATCH 1/6] cpuidle: sysfs: Fix the overlap for showing available governors Hanjun Guo
2020-05-19 15:43 ` Rafael J. Wysocki
2020-05-19 6:25 ` Hanjun Guo [this message]
2020-05-19 6:25 ` [PATCH 3/6] cpuidle: Make cpuidle governor switchable to be the default behaviour Hanjun Guo
2020-05-19 6:25 ` [PATCH 4/6] cpuidle: sysfs: Remove sysfs_switch and switch attributes Hanjun Guo
2020-05-19 6:25 ` [PATCH 5/6] Documentation: cpuidle: update the document Hanjun Guo
2020-05-19 6:25 ` [PATCH 6/6] Documentation: ABI: make current_governer_ro as a candidate for removal Hanjun Guo
2020-05-19 6:53 ` [PATCH 0/6] cpuidle: Make cpuidle governor switchable to be the default behaviour Hanjun Guo
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