diff options
| author | Mark Kettenis <kettenis@cvs.openbsd.org> | 2016-08-16 08:15:05 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@cvs.openbsd.org> | 2016-08-16 08:15:05 +0000 |
| commit | 5773d1d899e889acd90b39c4f79646579fd69368 (patch) | |
| tree | 39c1bed9746f9ef33650b1eb4e2eeacefd2f61fc /sys | |
| parent | 195f022803e0d657eaccff11bf54c3c62ee1b985 (diff) | |
Only probe the UART type if sc_uarttype is set to COM_UART_UNKNOWN.
This allows glue drivers to set the type based on other information (such as
Oopen Firmware or device tree properties) without going through to risky
code paths.
ok deraadt@, visa@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/dev/ic/com.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c index 000eea37cb9..b378ffc3696 100644 --- a/sys/dev/ic/com.c +++ b/sys/dev/ic/com.c @@ -1,4 +1,4 @@ -/* $OpenBSD: com.c,v 1.158 2014/09/14 14:17:24 jsg Exp $ */ +/* $OpenBSD: com.c,v 1.159 2016/08/16 08:15:04 kettenis Exp $ */ /* $NetBSD: com.c,v 1.82.4.1 1996/06/02 09:08:00 mrg Exp $ */ /* @@ -1583,6 +1583,7 @@ com_attach_subr(struct com_softc *sc) { bus_space_tag_t iot = sc->sc_iot; bus_space_handle_t ioh = sc->sc_ioh; + int probe = 0; u_int8_t lcr; sc->sc_ier = 0; @@ -1616,7 +1617,7 @@ com_attach_subr(struct com_softc *sc) /* * Skip specific probes if attachment code knows it already. */ - if (sc->sc_uarttype == COM_UART_UNKNOWN) + if (sc->sc_uarttype == COM_UART_UNKNOWN) { switch (bus_space_read_1(iot, ioh, com_iir) >> 6) { case 0: sc->sc_uarttype = COM_UART_16450; @@ -1631,8 +1632,11 @@ com_attach_subr(struct com_softc *sc) sc->sc_uarttype = COM_UART_UNKNOWN; break; } + probe = 1; + } - if (sc->sc_uarttype == COM_UART_16550A) { /* Probe for ST16650s */ + /* Probe for ST16650s */ + if (probe && sc->sc_uarttype == COM_UART_16550A) { bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB); if (bus_space_read_1(iot, ioh, com_efr) == 0) { bus_space_write_1(iot, ioh, com_efr, EFR_CTS); @@ -1647,7 +1651,8 @@ com_attach_subr(struct com_softc *sc) } #if 0 /* until com works with large FIFOs */ - if (sc->sc_uarttype == COM_UART_ST16650V2) { /* Probe for XR16850s */ + /* Probe for XR16850s */ + if (probe && sc->sc_uarttype == COM_UART_ST16650V2) { u_int8_t dlbl, dlbh; /* Enable latch access and get the current values. */ @@ -1670,7 +1675,8 @@ com_attach_subr(struct com_softc *sc) } #endif - if (sc->sc_uarttype == COM_UART_16550A) { /* Probe for TI16750s */ + /* Probe for TI16750s */ + if (probe && sc->sc_uarttype == COM_UART_16550A) { bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB); bus_space_write_1(iot, ioh, com_fifo, FIFO_ENABLE | FIFO_ENABLE_64BYTE); @@ -1686,7 +1692,9 @@ com_attach_subr(struct com_softc *sc) /* Reset the LCR (latch access is probably enabled). */ bus_space_write_1(iot, ioh, com_lcr, lcr); - if (sc->sc_uarttype == COM_UART_16450) { /* Probe for 8250 */ + + /* Probe for 8250 */ + if (probe && sc->sc_uarttype == COM_UART_16450) { u_int8_t scr0, scr1, scr2; scr0 = bus_space_read_1(iot, ioh, com_scratch); |