Fix races between timeouts and interrupts.

Cleanup atapiscsi driver a bit by moving fields out of xfer.

3 files changed, 214 insertions, 202 deletions

diff --git a/sys/dev/atapiscsi/atapiscsi.c b/sys/dev/atapiscsi/atapiscsi.c
index 539c2bba649..9aa669f3274 100644
--- a/sys/dev/atapiscsi/atapiscsi.c
+++ b/sys/dev/atapiscsi/atapiscsi.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: atapiscsi.c,v 1.37 2001/03/05 16:04:12 ho Exp $     */
+/*      $OpenBSD: atapiscsi.c,v 1.38 2001/03/15 23:08:16 csapuntz Exp $     */
 
 /*
  * This code is derived from code with the copyright below.
@@ -109,36 +109,37 @@ void  wdc_atapi_start __P((struct channel_softc *,struct wdc_xfer *));
 
 void  wdc_atapi_timer_handler __P((void *));
 
-int   wdc_atapi_real_start __P((struct channel_softc *, struct wdc_xfer *,
-    int));
-int   wdc_atapi_real_start_2 __P((struct channel_softc *, struct wdc_xfer *,
-    int));
-int   wdc_atapi_intr_command __P((struct channel_softc *, struct wdc_xfer *,
-    int));
-
-int   wdc_atapi_intr_data __P((struct channel_softc *, struct wdc_xfer *,
-    int));
-int   wdc_atapi_intr_complete __P((struct channel_softc *, struct wdc_xfer *,
-    int));
-
-int   wdc_atapi_intr_for_us __P((struct channel_softc *, struct wdc_xfer *,
-    int));
-
-int   wdc_atapi_send_packet __P((struct channel_softc *, struct wdc_xfer *,
-    int));
+void  wdc_atapi_real_start __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
+void  wdc_atapi_real_start_2 __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
+void  wdc_atapi_intr_command __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
+void  wdc_atapi_intr_data __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
+void  wdc_atapi_intr_complete __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
+void  wdc_atapi_intr_for_us __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
+void  wdc_atapi_send_packet __P((struct channel_softc *, struct wdc_xfer *,
+    int, struct atapi_return_args *));
 int   wdc_atapi_dma_flags __P((struct wdc_xfer *));
+void  wdc_atapi_ctrl __P((struct channel_softc *, struct wdc_xfer *, 
+    int, struct atapi_return_args *));
 
-int   wdc_atapi_ctrl __P((struct channel_softc *, struct wdc_xfer *, int));
 char  *wdc_atapi_in_data_phase __P((struct wdc_xfer *, int, int));
 
 int   wdc_atapi_intr __P((struct channel_softc *, struct wdc_xfer *, int));
-
-int   wdc_atapi_done __P((struct channel_softc *, struct wdc_xfer *, int));
-int   wdc_atapi_reset __P((struct channel_softc *, struct wdc_xfer *, int));
-int   wdc_atapi_reset_2 __P((struct channel_softc *, struct wdc_xfer *, int));
+void  wdc_atapi_done __P((struct channel_softc *, struct wdc_xfer *,
+	int, struct atapi_return_args *));
+void  wdc_atapi_reset __P((struct channel_softc *, struct wdc_xfer *,
+	int, struct atapi_return_args *));
+void  wdc_atapi_reset_2 __P((struct channel_softc *, struct wdc_xfer *,
+	int, struct atapi_return_args *));
 int   wdc_atapi_send_cmd __P((struct scsi_xfer *sc_xfer));
 
-int   wdc_atapi_tape_done __P((struct channel_softc *, struct wdc_xfer *, int));
+void  wdc_atapi_tape_done __P((struct channel_softc *, struct wdc_xfer *,
+	int, struct atapi_return_args *));
 #define MAX_SIZE MAXPHYS
 
 struct atapiscsi_softc;
@@ -147,13 +148,8 @@ struct atapiscsi_xfer;
 int	atapiscsi_match __P((struct device *, void *, void *));
 void	atapiscsi_attach __P((struct device *, struct device *, void *));
 
-int	wdc_atapi_get_params __P((struct channel_softc *, u_int8_t, struct ataparams *)); 
-
-int	atapi_dsc_wait __P((struct ata_drive_datas *, int));
-int	atapi_dsc_ready __P((void *));
-void    atapi_dsc_check __P((void *));
-int	atapi_dsc_semiready __P((void *));
-int	atapi_poll_wait __P((int (*) __P((void *)), void *, int, int, char *));
+int	wdc_atapi_get_params __P((struct channel_softc *, u_int8_t, 
+				     struct ataparams *)); 
 int     atapi_to_scsi_sense __P((struct scsi_xfer *, u_int8_t));
 
 struct atapiscsi_softc {
@@ -444,7 +440,7 @@ wdc_atapi_send_cmd(sc_xfer)
 	xfer->c_start = wdc_atapi_start;
 	xfer->c_intr = wdc_atapi_intr;
 
-	timeout_set(&xfer->atapi_poll_to, wdc_atapi_timer_handler, xfer);
+	timeout_set(&xfer->atapi_poll_to, wdc_atapi_timer_handler, chp);
 
 	s = splbio();
 
@@ -599,14 +595,19 @@ void
 wdc_atapi_timer_handler(arg)
 	void *arg;
 {
-	struct wdc_xfer *xfer = arg;
-	struct channel_softc *chp = xfer->chp;
+	struct channel_softc *chp = arg;
+	struct wdc_xfer *xfer;
 	int s;
 
-	xfer->c_flags &= ~C_POLL_MACHINE;
-
-	/* There is a race here between us and the interrupt */
 	s = splbio();
+	xfer = TAILQ_FIRST(&chp->ch_queue->sc_xfer);
+	if (xfer == NULL || 
+	    !timeout_triggered(&xfer->atapi_poll_to)) {
+		splx(s);
+		return;
+	}
+	xfer->c_flags &= ~C_POLL_MACHINE;
+	timeout_del(&xfer->atapi_poll_to);
 	chp->ch_flags &= ~WDCF_IRQ_WAIT;
 	wdc_atapi_the_machine(chp, xfer, ctxt_timer);
 	splx(s);
@@ -628,66 +629,63 @@ wdc_atapi_intr(chp, xfer, irq)
 	return (wdc_atapi_the_machine(chp, xfer, ctxt_interrupt));
 }
 
-#define CONTINUE_POLL 0
-#define GOTO_NEXT 1
-#define DONE 2
+struct atapi_return_args {
+	int timeout;
+	int delay; 
+	int expect_irq;
+	int claim_irq;
+};
+
+#define ARGS_INIT {-1, 0, 0, -1}
 
 int
 wdc_atapi_the_poll_machine(chp, xfer)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;	
 {
-	int  idx = 0, ret;
+	int  idx = 0;
 	int  current_timeout = 10;
 
-	xfer->timeout = -1;
 
 	while (1) {
+		struct atapi_return_args retargs = ARGS_INIT;
 		idx++;
 
-		xfer->timeout = -1;
-		xfer->delay = 0;
-		xfer->expect_irq = 0;
+		(xfer->next)(chp, xfer, (current_timeout * 1000 <= idx),
+		    &retargs);
 
-		ret = (xfer->next)(chp, xfer, (current_timeout * 1000 <= idx));
+		if (xfer->next == NULL) {
+			wdc_free_xfer(chp, xfer);
+			wdcstart(chp);
+			return (0);
+		}
 
-		if (xfer->timeout != -1) {
-			current_timeout = xfer->timeout;
+		if (retargs.timeout != -1) {
+			current_timeout = retargs.timeout;
 			idx = 0;
 		}
 
-		if (xfer->delay != 0) {
-			delay (1000 * xfer->delay);
-			idx += 1000 * xfer->delay;
+		if (retargs.delay != 0) {
+			delay (1000 * retargs.delay);
+			idx += 1000 * retargs.delay;
 		}
 
-		switch (ret) {
-		case GOTO_NEXT:
-			break;
-			
-	        case CONTINUE_POLL:
-			DELAY(1);
-			break;
-
-		case DONE:
-			wdc_free_xfer(chp, xfer);
-			wdcstart(chp);
-			return (0);
-		}
+		DELAY(1);
 	}
 }
 
+
 int
 wdc_atapi_the_machine(chp, xfer, ctxt)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;	
 	enum atapi_context ctxt;
 {
-	int idx = 0, ret;
+	int idx = 0;
 	int claim_irq = 0;
 	extern int ticks;
 	int timeout_delay = hz / 10;
-
+	
 	if (xfer->c_flags & C_POLL) {
 		if (ctxt != ctxt_process) 
 			return (0);
@@ -696,57 +694,49 @@ wdc_atapi_the_machine(chp, xfer, ctxt)
 		return (0);
 	}
 
- do_op:
-	idx++;
+	/* Don't go through more than 50 state machine steps
+	   before yielding. This tries to limit the amount of time
+	   spent at high SPL */
+	for (idx = 0; idx < 50; idx++) {
+		struct atapi_return_args retargs = ARGS_INIT;
 
-	xfer->timeout = -1;
-	xfer->claim_irq = 0;
-	xfer->delay = 0;
-
-	ret = (xfer->next)(chp, xfer, 
-			   xfer->endticks && (ticks - xfer->endticks >= 0));
-
-	if (xfer->timeout != -1) 
-		/*
-		 * Add 1 tick to compensate for the fact that we can be just
-		 * microseconds before the tick changes.
-		 */
-		xfer->endticks =
-		    max((xfer->timeout * hz) / 1000, 1) + 1 + ticks;
+		(xfer->next)(chp, xfer, 
+		    xfer->endticks && (ticks - xfer->endticks >= 0),
+		    &retargs);
+		
+		if (retargs.timeout != -1) 
+			/*
+			 * Add 1 tick to compensate for the fact that we 
+			 * can be just microseconds before the tick changes.
+			 */
+			xfer->endticks =
+			    max((retargs.timeout * hz) / 1000, 1) + 1 + ticks;
 
-	if (xfer->claim_irq) claim_irq = xfer->claim_irq;
+		if (retargs.claim_irq) claim_irq = retargs.claim_irq;
+		
+		if (xfer->next == NULL) {
+			if (xfer->c_flags & C_POLL_MACHINE)
+				timeout_del(&xfer->atapi_poll_to);
+			
+			wdc_free_xfer(chp, xfer);
+			wdcstart(chp);
+			
+			return (claim_irq);
+		}
 
-	if (xfer->delay) timeout_delay = max(xfer->delay * hz / 1000, 1);
+		if (retargs.delay) 
+			timeout_delay = max(retargs.delay * hz / 1000, 1);
 
-	switch (ret) {
-	case GOTO_NEXT:
-		if (xfer->expect_irq) {
+		if (retargs.expect_irq) {
 			chp->ch_flags |= WDCF_IRQ_WAIT;
-			xfer->expect_irq = 0;
 			timeout_add(&chp->ch_timo, xfer->endticks - ticks);
 			return (claim_irq);
 		}
-
-		if (xfer->delay)
+		
+		if (retargs.delay != 0)
 			break;
 
-		goto do_op;
-
-	case CONTINUE_POLL:
-		if (xfer->delay) break;
-		if (idx >= 50) break;
-
 		DELAY(1);
-		goto do_op;
-
-	case DONE:
-		if (xfer->c_flags & C_POLL_MACHINE)
-			timeout_del(&xfer->atapi_poll_to);
-
-		wdc_free_xfer(chp, xfer);
-		wdcstart(chp);
-
-		return (claim_irq);
 	}
 
 	timeout_add(&xfer->atapi_poll_to, timeout_delay);
@@ -773,11 +763,12 @@ wdc_atapi_update_status(chp)
 		chp->ch_error = CHP_READ_REG(chp, wdr_error);
 }
 
-int
-wdc_atapi_real_start(chp, xfer, timeout)
+void
+wdc_atapi_real_start(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 #ifdef WDCDEBUG
 	struct scsi_xfer *sc_xfer = xfer->cmd;
@@ -808,17 +799,18 @@ wdc_atapi_real_start(chp, xfer, timeout)
 	DELAY(1);
 
 	xfer->next = wdc_atapi_real_start_2;
-	xfer->timeout = ATAPI_DELAY;
+	ret->timeout = ATAPI_DELAY;
 
-	return (GOTO_NEXT);
+	return;
 }
 
 
-int
-wdc_atapi_real_start_2(chp, xfer, timeout)
+void
+wdc_atapi_real_start_2(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -829,12 +821,12 @@ wdc_atapi_real_start_2(chp, xfer, timeout)
 
 		sc_xfer->error = XS_TIMEOUT;
 		xfer->next = wdc_atapi_reset;
-		return (GOTO_NEXT);
+		return;
 	} else {
 		wdc_atapi_update_status(chp);
 		
 		if (chp->ch_status & WDCS_BSY)
-			return (CONTINUE_POLL);
+			return;
 	}
     
 	/* Do control operations specially. */
@@ -847,19 +839,20 @@ wdc_atapi_real_start_2(chp, xfer, timeout)
 		}
 
 		xfer->next = wdc_atapi_ctrl;
-		return (GOTO_NEXT);
+		return;
 	}
 
 	xfer->next = wdc_atapi_send_packet;
-	return (GOTO_NEXT);
+	return;
 }
 
 
-int
-wdc_atapi_send_packet(chp, xfer, timeout)
+void
+wdc_atapi_send_packet(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -885,13 +878,13 @@ wdc_atapi_send_packet(chp, xfer, timeout)
 	DELAY(1);
 
 	xfer->next = wdc_atapi_intr_for_us;
-	xfer->timeout = sc_xfer->timeout;
+	ret->timeout = sc_xfer->timeout;
 
 	if ((drvp->atapi_cap & ATAPI_CFG_DRQ_MASK) == ATAPI_CFG_IRQ_DRQ) {
 		/* We expect an IRQ to tell us of the next state */
-		xfer->expect_irq = 1;
+		ret->expect_irq = 1;
 	}
-	return (GOTO_NEXT);
+	return;
 }
 
 int
@@ -908,11 +901,12 @@ wdc_atapi_dma_flags(xfer)
 	return (dma_flags);
 }
 
-int
-wdc_atapi_intr_command(chp, xfer, timeout)
+void
+wdc_atapi_intr_command(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -946,7 +940,7 @@ wdc_atapi_intr_command(chp, xfer, timeout)
 			sc_xfer->error = XS_DRIVER_STUFFUP;
 
 			xfer->next = wdc_atapi_done;
-			return (GOTO_NEXT);
+			return;
 		}
 	}
 
@@ -964,7 +958,7 @@ wdc_atapi_intr_command(chp, xfer, timeout)
 	else
 		as->protocol_phase = as_data;
 
-	xfer->expect_irq = 1;
+	ret->expect_irq = 1;
 
 	/* If we read/write to a tape we will get into buffer
 	   availability mode.  */
@@ -985,7 +979,7 @@ wdc_atapi_intr_command(chp, xfer, timeout)
 		}
 	}
 
-	return (GOTO_NEXT);
+	return;
 }
 
 
@@ -1040,11 +1034,12 @@ wdc_atapi_in_data_phase(xfer, len, ire)
 	return (message);
 }
 
-int
-wdc_atapi_intr_data(chp, xfer, timeout)
+void
+wdc_atapi_intr_data(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -1063,8 +1058,8 @@ wdc_atapi_intr_data(chp, xfer, timeout)
 		   Give the drive 100ms to get its house in order
 		   before we try again.  */
 		if (!timeout) {
-			xfer->delay = 100;
-			return (CONTINUE_POLL);	
+			ret->delay = 100;
+			return;	
 		}
 	}
 
@@ -1073,7 +1068,7 @@ wdc_atapi_intr_data(chp, xfer, timeout)
 		
 		sc_xfer->error = XS_RESET;
 		xfer->next = wdc_atapi_reset;
-		return (GOTO_NEXT);
+		return;
 	}
 
 	
@@ -1121,19 +1116,19 @@ wdc_atapi_intr_data(chp, xfer, timeout)
 		xfer->c_bcount = 0;
 	}
 
-	xfer->expect_irq = 1;
+	ret->expect_irq = 1;
 	xfer->next = wdc_atapi_intr_for_us;
 
-	return (GOTO_NEXT);
+	return;
 }
 
 
-int
-wdc_atapi_intr_complete(chp, xfer, timeout)
+void
+wdc_atapi_intr_complete(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
-
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -1161,7 +1156,7 @@ wdc_atapi_intr_complete(chp, xfer, timeout)
 						"calling wdc_atapi_done()"
 					), DEBUG_INTR);
 				xfer->next = wdc_atapi_done;
-				return (GOTO_NEXT);
+				return;
 			}
 
 			/*
@@ -1171,7 +1166,7 @@ wdc_atapi_intr_complete(chp, xfer, timeout)
 
 			sc_xfer->error = XS_RESET;
 			xfer->next = wdc_atapi_reset;
-			return (GOTO_NEXT);
+			return;
 
 		} else if (xfer->c_bcount < sizeof(sc_xfer->sense)) {
 				/* use the sense we just read */
@@ -1199,7 +1194,7 @@ wdc_atapi_intr_complete(chp, xfer, timeout)
 				xfer->c_done = NULL;
 				xfer->c_flags |= C_SENSE;
 				xfer->next = wdc_atapi_real_start;
-				return (GOTO_NEXT);
+				return;
 			}
 		}		
 	}
@@ -1209,7 +1204,7 @@ wdc_atapi_intr_complete(chp, xfer, timeout)
 		sc_xfer->error = XS_RESET;
 
 		xfer->next = wdc_atapi_reset;
-		return (GOTO_NEXT);
+		return;
 	}
 			
 
@@ -1229,20 +1224,20 @@ wdc_atapi_intr_complete(chp, xfer, timeout)
 		       DEBUG_INTR);
 
 
-	if (xfer->c_done) 
+	if (xfer->c_done)
 		xfer->next = xfer->c_done;
 	else 
 		xfer->next = wdc_atapi_done;
 
-	return (GOTO_NEXT);
+	return;
 }
 
-int
-wdc_atapi_intr_for_us(chp, xfer, timeout)
+void
+wdc_atapi_intr_for_us(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
-
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -1263,29 +1258,29 @@ wdc_atapi_intr_for_us(chp, xfer, timeout)
 		
 		sc_xfer->error = XS_TIMEOUT;
 		xfer->next = wdc_atapi_reset;
-		return (GOTO_NEXT);
+		return;
 	}
 
 
 	if (chp->ch_status & WDCS_BSY)
-		return (CONTINUE_POLL);
+		return;
 
 	if (!wdc_atapi_drive_selected(chp, xfer->drive))
 	{
 		CHP_WRITE_REG(chp, wdr_sdh, WDSD_IBM | (xfer->drive << 4));
 		delay (1);
 		
-		return (CONTINUE_POLL);
+		return;
 	}
 
 	if (as->protocol_phase != as_cmdout &&
 	    (xfer->c_flags & C_MEDIA_ACCESS) &&
 	    !(chp->ch_status & (WDCS_DSC | WDCS_DRQ))) {
-		xfer->delay = 100;
-		return (CONTINUE_POLL);
+		ret->delay = 100;
+		return;
 	}
 
-	xfer->claim_irq = 1;
+	ret->claim_irq = -1;
 
 	ireason = CHP_READ_REG(chp, wdr_ireason);
 	WDCDEBUG_PRINT(("(%x, %x) ", chp->ch_status, ireason), DEBUG_INTR );
@@ -1293,37 +1288,42 @@ wdc_atapi_intr_for_us(chp, xfer, timeout)
 	switch (as->protocol_phase) {
 	case as_cmdout:
 		if (!(chp->ch_status & WDCS_DRQ))
-			return (CONTINUE_POLL);
+			return;
 
-		return (wdc_atapi_intr_command(chp, xfer, timeout));
+		wdc_atapi_intr_command(chp, xfer, timeout, ret);
+		return;
 
 	case as_data:
 		if ((chp->ch_status & WDCS_DRQ) ||
-		    (ireason & 3) != 3)
-			return (wdc_atapi_intr_data(chp, xfer, timeout));
+		    (ireason & 3) != 3) {
+			wdc_atapi_intr_data(chp, xfer, timeout, ret);
+			return;
+		}
 
 	case as_completed:
 		if ((chp->ch_status & WDCS_DRQ) ||
 		    (ireason & 3) != 3) {
-			xfer->delay = 100;
-			return (CONTINUE_POLL);
+			ret->delay = 100;
+			return;
 		}
 
-		return (wdc_atapi_intr_complete(chp, xfer, timeout));
+		wdc_atapi_intr_complete(chp, xfer, timeout, ret);
+		return;
 
 	default:
 		printf ("atapiscsi: Shouldn't get here\n");
 		sc_xfer->error = XS_DRIVER_STUFFUP;
 		xfer->next = wdc_atapi_reset;
-		return (GOTO_NEXT);
+		return;
 	}
 }
 
-int
-wdc_atapi_ctrl(chp, xfer, timeout)
+void
+wdc_atapi_ctrl(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -1360,25 +1360,25 @@ wdc_atapi_ctrl(chp, xfer, timeout)
 #endif
 			sc_xfer->error = XS_DRIVER_STUFFUP;
 			xfer->next = wdc_atapi_done;
-			return (GOTO_NEXT);
+			return;
 		}
 	}
 
 	wdc_atapi_update_status(chp);
 
 	if (chp->ch_status & WDCS_BSY)
-		return (CONTINUE_POLL);
+		return;
 
 	if (!wdc_atapi_drive_selected(chp, xfer->drive))
 	{
 		CHP_WRITE_REG(chp, wdr_sdh, WDSD_IBM | (xfer->drive << 4));
 		delay (1);
 
-		return (CONTINUE_POLL);
+		return;
 	}
 
 
-	xfer->claim_irq = 1;
+	ret->claim_irq = -1;
 
 	WDCDEBUG_PRINT(("wdc_atapi_ctrl %s:%d:%d state %d\n",
 	    chp->wdc->sc_dev.dv_xname, chp->channel, drvp->drive, drvp->state),
@@ -1392,8 +1392,8 @@ wdc_atapi_ctrl(chp, xfer, timeout)
 	case IDENTIFY:
 		wdccommandshort(chp, drvp->drive, ATAPI_IDENTIFY_DEVICE);
 		drvp->state = IDENTIFY_WAIT;
-		xfer->timeout = ATAPI_CTRL_WAIT;
-		xfer->expect_irq = 1;
+		ret->timeout = ATAPI_CTRL_WAIT;
+		ret->expect_irq = 1;
 		break;
 	
 	case IDENTIFY_WAIT:
@@ -1402,7 +1402,7 @@ wdc_atapi_ctrl(chp, xfer, timeout)
 		if (!(chp->ch_status & WDCS_ERR)) {
 			wdcbit_bucket(chp, 512);
 	
-			xfer->timeout = 100;
+			ret->timeout = 100;
 			drvp->state = PIOMODE;
 			break;
 		}
@@ -1420,8 +1420,8 @@ piomode:
 		wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
 		    0x08 | drvp->PIO_mode, WDSF_SET_MODE);
 		drvp->state = PIOMODE_WAIT;
-		xfer->timeout = ATAPI_CTRL_WAIT;
-		xfer->expect_irq = 1;
+		ret->timeout = ATAPI_CTRL_WAIT;
+		ret->expect_irq = 1;
 		break;
 	case PIOMODE_WAIT:
 		if (chp->ch_status & WDCS_ERR) {
@@ -1458,8 +1458,8 @@ piomode:
 		}
 		drvp->state = DMAMODE_WAIT;
 
-		xfer->timeout = ATAPI_CTRL_WAIT;
-		xfer->expect_irq = 1;
+		ret->timeout = ATAPI_CTRL_WAIT;
+		ret->expect_irq = 1;
 		break;
 
 	case DMAMODE_WAIT:
@@ -1473,28 +1473,29 @@ piomode:
 		xfer->next = wdc_atapi_real_start;
 		break;
 	}
-	return (GOTO_NEXT);
+	return;
 
 timeout:
 	printf("%s:%d:%d: %s timed out\n",
 	    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive, errstring);
 	sc_xfer->error = XS_TIMEOUT;
 	xfer->next = wdc_atapi_reset;
-	return (GOTO_NEXT);
+	return;
 
 }
 
-int
-wdc_atapi_tape_done(chp, xfer, timeout)
+void
+wdc_atapi_tape_done(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 
 	if (sc_xfer->error != XS_NOERROR) {
 		xfer->next = wdc_atapi_done;
-		return (GOTO_NEXT);
+		return;
 	}
 
 	_lto3b(xfer->transfer_len,
@@ -1506,15 +1507,16 @@ wdc_atapi_tape_done(chp, xfer, timeout)
 	xfer->c_skip = 0;
 
 	xfer->next = wdc_atapi_real_start;
-	return (GOTO_NEXT);
+	return;
 }
 
 	
-int
-wdc_atapi_done(chp, xfer, timeout)
+void
+wdc_atapi_done(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct scsi_xfer *sc_xfer = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
@@ -1541,15 +1543,17 @@ wdc_atapi_done(chp, xfer, timeout)
 		scsi_done(sc_xfer);
 	}
 
-	return (DONE);
+	xfer->next = NULL;
+	return;
 }
 
 
-int
-wdc_atapi_reset(chp, xfer, timeout)
+void
+wdc_atapi_reset(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
 
@@ -1560,16 +1564,17 @@ wdc_atapi_reset(chp, xfer, timeout)
 	   brains after a reset
 	 */
 	xfer->next = wdc_atapi_reset_2;
-	xfer->delay = 10;
-	xfer->timeout = ATAPI_RESET_WAIT;
-	return (GOTO_NEXT);
+	ret->delay = 10;
+	ret->timeout = ATAPI_RESET_WAIT;
+	return;
 }
 
-int
-wdc_atapi_reset_2(chp, xfer, timeout)
+void
+wdc_atapi_reset_2(chp, xfer, timeout, ret)
 	struct channel_softc *chp;
 	struct wdc_xfer *xfer;
 	int timeout;
+	struct atapi_return_args *ret;
 {
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
 	struct scsi_xfer *sc_xfer = xfer->cmd;
@@ -1582,16 +1587,16 @@ wdc_atapi_reset_2(chp, xfer, timeout)
 		wdc_reset_channel(drvp);
 		
 		xfer->next = wdc_atapi_done;
-		return (GOTO_NEXT);
+		return;
 	}
 
 	wdc_atapi_update_status(chp);
 
 	if (chp->ch_status & (WDCS_BSY | WDCS_DRQ)) {
-		return (CONTINUE_POLL);
+		return;
 	}
 
 	xfer->next = wdc_atapi_done;
-	return (GOTO_NEXT);
+	return;
 }
 
diff --git a/sys/dev/ic/wdc.c b/sys/dev/ic/wdc.c
index e8ebd216814..575b40474f0 100644
--- a/sys/dev/ic/wdc.c
+++ b/sys/dev/ic/wdc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: wdc.c,v 1.26 2001/01/29 02:18:33 niklas Exp $     */
+/*      $OpenBSD: wdc.c,v 1.27 2001/03/15 23:08:16 csapuntz Exp $     */
 /*	$NetBSD: wdc.c,v 1.68 1999/06/23 19:00:17 bouyer Exp $ */
 
 
@@ -1094,12 +1094,20 @@ wdctimeout(arg)
 	void *arg;
 {
 	struct channel_softc *chp = (struct channel_softc *)arg;
-	struct wdc_xfer *xfer = chp->ch_queue->sc_xfer.tqh_first;
+	struct wdc_xfer *xfer;
 	int s;
 
 	WDCDEBUG_PRINT(("wdctimeout\n"), DEBUG_FUNCS);
 
 	s = splbio();
+	xfer = TAILQ_FIRST(&chp->ch_queue->sc_xfer);
+
+	/* Did we lose a race with the interrupt? */
+	if (xfer == NULL ||
+	    !timeout_triggered(&chp->ch_timo)) {
+		splx(s);
+		return;
+	}	
 	if ((chp->ch_flags & WDCF_IRQ_WAIT) != 0) {
 		__wdcerror(chp, "timeout");
 		printf("\ttype: %s\n", (xfer->c_flags & C_ATAPI) ?
diff --git a/sys/dev/ic/wdcvar.h b/sys/dev/ic/wdcvar.h
index 7d444b59fd2..76f227cdacc 100644
--- a/sys/dev/ic/wdcvar.h
+++ b/sys/dev/ic/wdcvar.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: wdcvar.h,v 1.14 2001/03/05 16:04:11 ho Exp $     */
+/*      $OpenBSD: wdcvar.h,v 1.15 2001/03/15 23:08:16 csapuntz Exp $     */
 /*	$NetBSD: wdcvar.h,v 1.17 1999/04/11 20:50:29 bouyer Exp $	*/
 
 /*-
@@ -186,6 +186,8 @@ struct wdc_softc { /* Per controller state */
   * Description of a command to be handled by a controller.
   * These commands are queued in a list.
   */
+struct atapi_return_args;
+
 struct wdc_xfer {
 	volatile u_int c_flags;    
 #define C_INUSE  	0x0001 /* xfer struct is in use */
@@ -211,18 +213,15 @@ struct wdc_xfer {
 	LIST_ENTRY(wdc_xfer) free_list;
 	void (*c_start) __P((struct channel_softc *, struct wdc_xfer *));
 	int  (*c_intr)  __P((struct channel_softc *, struct wdc_xfer *, int));
-	int (*c_done)  __P((struct channel_softc *, struct wdc_xfer *, int));
         void (*c_kill_xfer) __P((struct channel_softc *, struct wdc_xfer *));
 
 	/* Used by ATAPISCSI */
-	int timeout;
-	int endticks;
-	int delay;
+ 	int endticks;
 	struct timeout atapi_poll_to;
-	unsigned int expect_irq:1;
-	unsigned int claim_irq:1;
-
-	int (*next) __P((struct channel_softc *, struct wdc_xfer *, int));
+	void (*next) __P((struct channel_softc *, struct wdc_xfer *, int,
+			 struct atapi_return_args *));
+	void (*c_done)  __P((struct channel_softc *, struct wdc_xfer *, int,
+			 struct atapi_return_args *));
 	
 	/* Used for tape devices */
 	int  transfer_len;