[igt-dev] [PATCH igt] overlay: Call setlocale around strtod

[Chris Wilson]

strtod() is locale-dependent. The decimal conversion depends on the radix
character ('.' for some of us like myself) varies by locale. As the
kernel reports its values using the "C" locale, we need to switch to
that when parsing; and switch back before reporting to the user.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105712
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 overlay/power.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/overlay/power.c b/overlay/power.c
index 9ac90fde..0f99e2a4 100644
--- a/overlay/power.c
+++ b/overlay/power.c
@@ -31,6 +31,7 @@
 #include <time.h>
 #include <errno.h>
 #include <ctype.h>
+#include <locale.h>
 #include <math.h>
 
 #include "igt_perf.h"
@@ -97,12 +98,18 @@ static uint64_t rapl_gpu_power(void)
 
 static double filename_to_double(const char *filename)
 {
-	char buf[64];
+	char *oldlocale;
+	char buf[80];
+	double v;
 
 	if (filename_to_buf(filename, buf, sizeof(buf)))
 		return 0;
 
-	return strtod(buf, NULL);
+	oldlocale = setlocale(LC_ALL, "C");
+	v = strtod(buf, NULL);
+	setlocale(LC_ALL, oldlocale);
+
+	return v;
 }
 
 static double rapl_gpu_power_scale(void)
-- 
2.16.3