diff options
author | John Kacur <jkacur@redhat.com> | 2014-08-14 16:03:07 +0200 |
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committer | John Kacur <jkacur@redhat.com> | 2014-08-14 16:03:07 +0200 |
commit | 4b430a76785d630e399e60466fdc66cec3a74805 (patch) | |
tree | 03ecad55f96b3a43c24728024cc9bee1a38fe12d | |
parent | 245b19c5f69a00f36bb17adbaf0472a45ac06154 (diff) | |
download | rt-tests-4b430a76785d630e399e60466fdc66cec3a74805.tar.gz |
cyclictest: Always print an err message if write of 0 to cpu-dma_latency fails
In set_latency_target() there are some paths that don't print an error
message even when a write of 0 to /dev/cpu_dma_latency fails.
This patch does the following
- always print an error message if the write to /dev/cpu_dma_latency
fails
- Fix the error check with the write call. (a return of 0 or -1 indicate
problems
- rename ret to err since this function is void and returns no value
- use err_msg_n instead of printf (which also prints to stderr)
Signed-off-by: John Kacur <jkacur@redhat.com>
-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); } |