diff options
| -rw-r--r-- | cpukit/score/src/kern_tc.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c index bb8a3f110d..e6e952facd 100644 --- a/cpukit/score/src/kern_tc.c +++ b/cpukit/score/src/kern_tc.c @@ -242,6 +242,8 @@ SYSCTL_PROC(_kern_timecounter, OID_AUTO, alloweddeviation, CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, 0, sysctl_kern_timecounter_adjprecision, "I", "Allowed time interval deviation in percents"); + +static int tc_chosen; /* Non-zero if a specific tc was chosen via sysctl. */ #endif /* __rtems__ */ static void tc_windup(void); @@ -1344,10 +1346,13 @@ tc_init(struct timecounter *tc) "quality", CTLFLAG_RD, &(tc->tc_quality), 0, "goodness of time counter"); /* - * Never automatically use a timecounter with negative quality. + * Do not automatically switch if the current tc was specifically + * chosen. Never automatically use a timecounter with negative quality. * Even though we run on the dummy counter, switching here may be - * worse since this timecounter may not be monotonous. + * worse since this timecounter may not be monotonic. */ + if (tc_chosen) + return; if (tc->tc_quality < 0) return; if (tc->tc_quality < timecounter->tc_quality) @@ -1630,9 +1635,12 @@ sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) strlcpy(newname, tc->tc_name, sizeof(newname)); error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); - if (error != 0 || req->newptr == NULL || - strcmp(newname, tc->tc_name) == 0) + if (error != 0 || req->newptr == NULL) return (error); + /* Record that the tc in use now was specifically chosen. */ + tc_chosen = 1; + if (strcmp(newname, tc->tc_name) == 0) + return (0); for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { if (strcmp(newname, newtc->tc_name) != 0) continue; @@ -1661,7 +1669,7 @@ SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, "Timecounter hardware selected"); -/* Report or change the active timecounter hardware. */ +/* Report the available timecounter hardware. */ static int sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) { |