diff options
Diffstat (limited to 'src/cyclictest/cyclictest.c')
| -rw-r--r-- | src/cyclictest/cyclictest.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c index 01dfc75..64f1764 100644 --- a/src/cyclictest/cyclictest.c +++ b/src/cyclictest/cyclictest.c @@ -233,20 +233,30 @@ static int32_t latency_target_value = 0; static void set_latency_target(void) { struct stat s; - int ret; + int err; - if (stat("/dev/cpu_dma_latency", &s) == 0) { - latency_target_fd = open("/dev/cpu_dma_latency", O_RDWR); - if (latency_target_fd == -1) - return; - ret = write(latency_target_fd, &latency_target_value, 4); - if (ret == 0) { - printf("# error setting cpu_dma_latency to %d!: %s\n", latency_target_value, strerror(errno)); - close(latency_target_fd); - return; - } - printf("# /dev/cpu_dma_latency set to %dus\n", latency_target_value); + errno = 0; + err = stat("/dev/cpu_dma_latency", &s); + if (err == -1) { + err_msg_n(errno, "WARN: stat /dev/cpu_dma_latency failed"); + return; + } + + errno = 0; + latency_target_fd = open("/dev/cpu_dma_latency", O_RDWR); + if (latency_target_fd == -1) { + err_msg_n(errno, "WARN: open /dev/cpu_dma_latency"); + return; + } + + errno = 0; + err = write(latency_target_fd, &latency_target_value, 4); + if (err < 1) { + err_msg_n(errno, "# error setting cpu_dma_latency to %d!", latency_target_value); + close(latency_target_fd); + return; } + printf("# /dev/cpu_dma_latency set to %dus\n", latency_target_value); } |