Commit 4b972f0b authored by viresh kumar's avatar viresh kumar Committed by Rafael J. Wysocki
Browse files

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: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 8bf1ac72

drivers/cpufreq/cpufreq.c

+3 −3
Original line number Diff line number Diff line
@@ -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");

include/linux/cpufreq.h

+2 −0
Original line number Diff line number Diff line
@@ -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)





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