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cpufreq / core: Fix printing of governor and driver name 

Arrays for governer and driver name are of size CPUFREQ_NAME_LEN or 16.
i.e. 15 bytes for name and 1 for trailing '\0'.

When cpufreq driver print these names (for sysfs), it includes '\n' or ' ' in
the fmt string and still passes length as CPUFREQ_NAME_LEN. If the driver or
governor names are using all 15 fields allocated to them, then the trailing '\n'
or ' ' will never be printed. And so commands like:

root@linaro-developer# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver

will print something like:

cpufreq_foodrvroot@linaro-developer#

Fix this by increasing print length by one character.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
viresh kumar 2012-10-23 01:23:43 +02:00 committed by Rafael J. Wysocki
parent 8bf1ac7236
commit 4b972f0b04
2 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/cpufreq/cpufreq.c
View File

@ -445,7 +445,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
return sprintf(buf, "performance\n");
else if (policy->governor)
return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n",
return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
policy->governor->name);
return -EINVAL;
}
@ -491,7 +491,7 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
*/
static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
{
return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
}
/**
@ -512,7 +512,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
- (CPUFREQ_NAME_LEN + 2)))
goto out;
i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
}
out:
i += sprintf(&buf[i], "\n");

2
include/linux/cpufreq.h
View File

@ -22,6 +22,8 @@
#include <asm/div64.h>
#define CPUFREQ_NAME_LEN 16
/* Print length for names. Extra 1 space for accomodating '\n' in prints */
#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
/*********************************************************************