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@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 01dfc75fd70c..64f1764681b0 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);
}
--
1.8.1.4
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