From 265efbb2c4401542c8753e0d83d7a98493720865 Mon Sep 17 00:00:00 2001 From: Jeff McGee Date: Fri, 10 Jan 2014 15:12:30 -0600 Subject: [PATCH] pm_rps: Use unbuffered I/O on sysfs files Bionic C library may not re-read a buffered, read-only file which results in failure to monitor changes in gt_cur_freq_mhz. Signed-off-by: Jeff McGee Signed-off-by: Daniel Vetter --- tests/pm_rps.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/tests/pm_rps.c b/tests/pm_rps.c index e8affdb..9123451 100644 --- a/tests/pm_rps.c +++ b/tests/pm_rps.c @@ -22,6 +22,7 @@ * * Authors: * Ben Widawsky + * Jeff McGee * */ @@ -66,7 +67,6 @@ static int readval(FILE *filp) int val; int scanned; - fflush(filp); rewind(filp); scanned = fscanf(filp, "%d", &val); igt_assert(scanned == 1); @@ -76,15 +76,11 @@ static int readval(FILE *filp) static int do_writeval(FILE *filp, int val, int lerrno) { - /* Must write twice to sysfs since the first one simply calculates the size and won't return the error */ int ret; rewind(filp); ret = fprintf(filp, "%d", val); - rewind(filp); - ret = fprintf(filp, "%d", val); if (ret && lerrno) igt_assert(errno = lerrno); - fflush(filp); return ret; } #define writeval(filp, val) do_writeval(filp, val, 0) @@ -146,6 +142,7 @@ igt_simple_main igt_assert(ret != -1); junk->filp = fopen(path, junk->mode); igt_require(junk->filp); + setbuf(junk->filp, NULL); val = readval(junk->filp); igt_assert(val >= 0); -- 2.7.4