The PTP_CLOCK_GETCAPS2 ioctl is provided by kernel as a replacement for the
original PTP_CLOCK_GETCAPS ioctl. This was done in order to provide ioctls
which guarantee reserved fields are properly initialized. In practice the
PTP_CLOCK_GETCAPS2 and PTP_CLOCK_GETCAPS both behave identically since
PTP_CLOCK_GETCAPS always zeroed the caps structure. However, it is good
practice to use the newer version consistently.
Signed-off-by: Jacob Keller <jacob.e.kel...@intel.com>
---
Technically this is identical in current kernels, both ioctls return exactly
the same conent.. I still think its better to use the '2' variants in
principle that developer doesn't have to remember "is this variant ok to get
all the new features going forward?"
missing.h | 7 +++++++
phc_ctl.c | 2 +-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/missing.h b/missing.h
index 79a87d425993..41427d3a38b2 100644
--- a/missing.h
+++ b/missing.h
@@ -98,6 +98,13 @@ enum {
#define PTP_PEROUT_REQUEST2 PTP_PEROUT_REQUEST
#endif
+#ifdef PTP_CLOCK_GETCAPS2
+#define PTP_CLOCK_GETCAPS_REQUEST_FAILED "PTP_CLOCK_GETCAPS2 failed: %m"
+#else
+#define PTP_CLOCK_GETCAPS_REQUEST_FAILED "PTP_CLOCK_GETCAPS failed: %m"
+#define PTP_CLOCK_GETCAPS2 PTP_CLOCK_GETCAPS
+#endif
+
#if LINUX_VERSION_CODE < KERNEL_VERSION(5,8,0)
/* from upcoming Linux kernel version 5.8 */
diff --git a/phc_ctl.c b/phc_ctl.c
index 6a5c2f43d7c9..17a615f8aae6 100644
--- a/phc_ctl.c
+++ b/phc_ctl.c
@@ -288,7 +288,7 @@ static int do_caps(clockid_t clkid, int cmdc, char *cmdv[])
return 0;
}
- if (ioctl(CLOCKID_TO_FD(clkid), PTP_CLOCK_GETCAPS, &caps)) {
+ if (ioctl(CLOCKID_TO_FD(clkid), PTP_CLOCK_GETCAPS2, &caps)) {
pr_err("get capabilities failed: %s",
strerror(errno));
return -1;
--
2.38.1.420.g319605f8f00e
_______________________________________________
Linuxptp-devel mailing list
Linuxptp-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
