diff options
| author | marius <marius@FreeBSD.org> | 2005-06-04 23:24:50 +0000 |
|---|---|---|
| committer | marius <marius@FreeBSD.org> | 2005-06-04 23:24:50 +0000 |
| commit | c74fc16e2d53283bd07cca184cb14f3756e96cd6 (patch) | |
| tree | 0fdba4f2b7230bd94e29e31cbe9e619f8f262091 /sys/sparc64 | |
| parent | 9230b25dd78459f5e14760d924dafc0ab3c1a555 (diff) | |
| download | FreeBSD-src-c74fc16e2d53283bd07cca184cb14f3756e96cd6.zip FreeBSD-src-c74fc16e2d53283bd07cca184cb14f3756e96cd6.tar.gz | |
After some input from bde@ and rereading the datasheet use a MTX_SPIN
mutex instead of a MTX_DEF one in order to defer preemption while
reading the date and time registers. If we don't manage to read them
within the time slot where we are guaranteed that no updates occur we
might actually read them during an update in which case the output is
undefined.
Diffstat (limited to 'sys/sparc64')
| -rw-r--r-- | sys/sparc64/sparc64/rtc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sys/sparc64/sparc64/rtc.c b/sys/sparc64/sparc64/rtc.c index 234d1b7..be8e009 100644 --- a/sys/sparc64/sparc64/rtc.c +++ b/sys/sparc64/sparc64/rtc.c @@ -149,7 +149,7 @@ rtc_attach(device_t dev) sc = device_get_softc(dev); bzero(sc, sizeof(struct mc146818_softc)); - mtx_init(&sc->sc_mtx, "rtc_mtx", NULL, MTX_DEF); + mtx_init(&sc->sc_mtx, "rtc_mtx", NULL, MTX_SPIN); if (strcmp(device_get_name(device_get_parent(dev)), "isa") == 0) rtype = SYS_RES_IOPORT; |
