Revert previous commit; the XR17V35X probe that was added accesses registers

that aren't guaranteed to be there and may even belong to a different device.
This triggers a fault on hppa machines like the C3000 for example.

3 files changed, 6 insertions, 34 deletions

diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c
index d94cd170685..38ba49ca48d 100644
--- a/sys/dev/ic/com.c
+++ b/sys/dev/ic/com.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: com.c,v 1.167 2018/04/15 15:07:25 jcs Exp $	*/
+/*	$OpenBSD: com.c,v 1.168 2018/05/02 13:20:12 kettenis Exp $	*/
 /*	$NetBSD: com.c,v 1.82.4.1 1996/06/02 09:08:00 mrg Exp $	*/
 
 /*
@@ -306,9 +306,6 @@ comopen(dev_t dev, int flag, int mode, struct proc *p)
 			case COM_UART_TI16750:
 				com_write_reg(sc, com_ier, 0);
 				break;
-			case COM_UART_XR17V35X:
-				com_write_reg(sc, UART_EXAR_SLEEP, 0);
-				break;
 			}
 		}
 
@@ -501,9 +498,6 @@ compwroff(struct com_softc *sc)
 		case COM_UART_TI16750:
 			com_write_reg(sc, com_ier, IER_SLEEP);
 			break;
-		case COM_UART_XR17V35X:
-			com_write_reg(sc, UART_EXAR_SLEEP, 0xff);
-			break;
 		}
 	}
 }
@@ -539,9 +533,6 @@ com_resume(struct com_softc *sc)
 		case COM_UART_TI16750:
 			com_write_reg(sc, com_ier, 0);
 			break;
-		case COM_UART_XR17V35X:
-			com_write_reg(sc, UART_EXAR_SLEEP, 0);
-			break;
 		}
 	}
 
@@ -928,7 +919,7 @@ comstart(struct tty *tp)
 	}
 
 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
-		u_char buffer[256];	/* largest fifo */
+		u_char buffer[128];	/* largest fifo */
 		int i, n;
 
 		n = q_to_b(&tp->t_outq, buffer,
@@ -1317,7 +1308,7 @@ void
 com_attach_subr(struct com_softc *sc)
 {
 	int probe = 0;
-	u_int8_t lcr, dvid;
+	u_int8_t lcr;
 
 	sc->sc_ier = 0;
 	/* disable interrupts */
@@ -1364,13 +1355,6 @@ com_attach_subr(struct com_softc *sc)
 		probe = 1;
 	}
 
-	/* Probe for XR17V35X */
-	if (probe && sc->sc_uarttype == COM_UART_16550A) {
-		dvid = com_read_reg(sc, UART_EXAR_DVID);
-		if (dvid == 0x82 || dvid == 0x84 || dvid == 0x88)
-			sc->sc_uarttype = COM_UART_XR17V35X;
-	}
-
 	/* Probe for ST16650s */
 	if (probe && sc->sc_uarttype == COM_UART_16550A) {
 		com_write_reg(sc, com_lcr, lcr | LCR_DLAB);
@@ -1499,11 +1483,6 @@ com_attach_subr(struct com_softc *sc)
 		break;
 #endif
 #endif
-	case COM_UART_XR17V35X:
-		printf(": xr17v35x, 256 byte fifo\n");
-		SET(sc->sc_hwflags, COM_HW_FIFO);
-		sc->sc_fifolen = 256;
-		break;
 	default:
 		panic("comattach: bad fifo type");
 	}
@@ -1511,8 +1490,7 @@ com_attach_subr(struct com_softc *sc)
 #ifdef COM_CONSOLE
 	if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
 #endif
-		if (sc->sc_fifolen < 256)
-			com_fifo_probe(sc);
+		com_fifo_probe(sc);
 
 	if (sc->sc_fifolen == 0) {
 		CLR(sc->sc_hwflags, COM_HW_FIFO);
diff --git a/sys/dev/ic/comreg.h b/sys/dev/ic/comreg.h
index 96ee9fcc764..21ea12b4cd9 100644
--- a/sys/dev/ic/comreg.h
+++ b/sys/dev/ic/comreg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: comreg.h,v 1.18 2018/04/15 15:07:25 jcs Exp $	*/
+/*	$OpenBSD: comreg.h,v 1.19 2018/05/02 13:20:12 kettenis Exp $	*/
 /*	$NetBSD: comreg.h,v 1.8 1996/02/05 23:01:50 scottr Exp $	*/
 
 /*
@@ -182,11 +182,6 @@
 
 #define	COM_NPORTS	8
 
-/* Exar XR17V35X */
-#define UART_EXAR_INT0	0x80
-#define UART_EXAR_SLEEP	0x8b	/* Sleep mode */
-#define UART_EXAR_DVID	0x8d	/* Device identification */
-
 /*
  * WARNING: Serial console is assumed to be at COM1 address
  */
diff --git a/sys/dev/ic/comvar.h b/sys/dev/ic/comvar.h
index 0b75bb30172..a9909743961 100644
--- a/sys/dev/ic/comvar.h
+++ b/sys/dev/ic/comvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: comvar.h,v 1.55 2018/04/15 15:07:25 jcs Exp $	*/
+/*	$OpenBSD: comvar.h,v 1.56 2018/05/02 13:20:12 kettenis Exp $	*/
 /*	$NetBSD: comvar.h,v 1.5 1996/05/05 19:50:47 christos Exp $	*/
 
 /*
@@ -103,7 +103,6 @@ struct com_softc {
 #define	COM_UART_ST16C654	0x08		/* 64 bytes fifo */
 #define	COM_UART_XR16850	0x10		/* 128 byte fifo */
 #define	COM_UART_OX16C950	0x11		/* 128 byte fifo */
-#define	COM_UART_XR17V35X	0x12		/* 256 byte fifo */
 
 	u_char sc_hwflags;
 #define	COM_HW_NOIEN	0x01