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| author | Dale Rahn <drahn@cvs.openbsd.org> | 2011-05-22 22:36:54 +0000 |
|---|---|---|
| committer | Dale Rahn <drahn@cvs.openbsd.org> | 2011-05-22 22:36:54 +0000 |
| commit | 44f96cec27921325881829c52b084ed9b5f78668 (patch) | |
| tree | acb5f0dd2fd5a290787112dca31997b6b872995a | |
| parent | 8705bf0fc617b543ad97dde03b83f15330d1144d (diff) | |
Fix a problem found where one SOC has a uart implementation that causes bus
errors if the fifo is read when the fifo is empty. Dont read an empty fifo.
ok deraaadt@ fgsch@
| -rw-r--r-- | sys/dev/ic/com.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c index a85ddb5989d..03769a08109 100644 --- a/sys/dev/ic/com.c +++ b/sys/dev/ic/com.c @@ -1,4 +1,4 @@ -/* $OpenBSD: com.c,v 1.146 2011/03/23 15:51:11 fgsch Exp $ */ +/* $OpenBSD: com.c,v 1.147 2011/05/22 22:36:53 drahn Exp $ */ /* $NetBSD: com.c,v 1.82.4.1 1996/06/02 09:08:00 mrg Exp $ */ /* @@ -538,7 +538,8 @@ compwroff(struct com_softc *sc) */ bus_space_write_1(iot, ioh, com_fifo, 0); delay(100); - (void) bus_space_read_1(iot, ioh, com_data); + if (ISSET(bus_space_read_1(iot, ioh, com_lsr), LSR_RXRDY)) + (void) bus_space_read_1(iot, ioh, com_data); delay(100); bus_space_write_1(iot, ioh, com_fifo, FIFO_RCV_RST | FIFO_XMT_RST); |