diff --git a/sys/dev/ata/ata_wdc.c b/sys/dev/ata/ata_wdc.c
index 7791acbb7480..3da44e2b24ca 100644
--- a/sys/dev/ata/ata_wdc.c
+++ b/sys/dev/ata/ata_wdc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: ata_wdc.c,v 1.27 2000/05/15 08:32:07 bouyer Exp $	*/
+/*	$NetBSD: ata_wdc.c,v 1.28 2000/06/12 21:10:40 bouyer Exp $	*/
 
 /*
  * Copyright (c) 1998 Manuel Bouyer.
@@ -457,6 +457,8 @@ wdc_ata_bio_intr(chp, xfer, irq)
 		wdc_ata_bio_done(chp, xfer);
 		return 1;
 	}
+	if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+		chp->wdc->irqack(chp);
 	
 	drv_err = wdc_ata_err(drvp, ata_bio);
 
@@ -654,6 +656,8 @@ again:
 		errstring = "recal";
 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & (WDCS_ERR | WDCS_DWF))
 			goto error;
 	/* fall through */
@@ -674,6 +678,8 @@ again:
 		errstring = "piomode";
 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & (WDCS_ERR | WDCS_DWF))
 			goto error;
 	/* fall through */
@@ -694,6 +700,8 @@ again:
 		errstring = "dmamode";
 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & (WDCS_ERR | WDCS_DWF))
 			goto error;
 	/* fall through */
@@ -714,6 +722,8 @@ again:
 		errstring = "geometry";
 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & (WDCS_ERR | WDCS_DWF))
 			goto error;
 		/* fall through */
@@ -731,6 +741,8 @@ again:
 		errstring = "setmulti";
 		if (wdcwait(chp, WDCS_DRDY, WDCS_DRDY, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & (WDCS_ERR | WDCS_DWF))
 			goto error;
 		/* fall through */
diff --git a/sys/dev/ic/wdc.c b/sys/dev/ic/wdc.c
index 7aadd59677f1..f1e0076993b8 100644
--- a/sys/dev/ic/wdc.c
+++ b/sys/dev/ic/wdc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: wdc.c,v 1.90 2000/06/11 17:09:34 bouyer Exp $ */
+/*	$NetBSD: wdc.c,v 1.91 2000/06/12 21:10:41 bouyer Exp $ */
 
 
 /*
@@ -1323,6 +1323,8 @@ __wdccommand_intr(chp, xfer, irq)
 		__wdccommand_done(chp, xfer);
 		return 1;
 	}
+	if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+		chp->wdc->irqack(chp);
 	if (wdc_c->flags & AT_READ) {
 		if (chp->ch_drive[xfer->drive].drive_flags & DRIVE_CAP32) {
 			bus_space_read_multi_4(chp->data32iot, chp->data32ioh,
diff --git a/sys/dev/ic/wdcvar.h b/sys/dev/ic/wdcvar.h
index 4f42e0d46668..ffc856ebd338 100644
--- a/sys/dev/ic/wdcvar.h
+++ b/sys/dev/ic/wdcvar.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: wdcvar.h,v 1.24 2000/04/01 14:32:22 bouyer Exp $	*/
+/*	$NetBSD: wdcvar.h,v 1.25 2000/06/12 21:10:41 bouyer Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -98,6 +98,7 @@ struct wdc_softc { /* Per controller state */
 #define	WDC_CAPABILITY_ATAPI_NOSTREAM 0x0080 /* Don't use stream f on ATAPI */
 #define WDC_CAPABILITY_NO_EXTRA_RESETS 0x0100 /* only reset once */
 #define WDC_CAPABILITY_PREATA 0x0200 /* ctrl can be a pre-ata one */
+#define WDC_CAPABILITY_IRQACK 0x0400 /* callback to ack interrupt */
 	u_int8_t      PIO_cap; /* highest PIO mode supported */
 	u_int8_t      DMA_cap; /* highest DMA mode supported */
 	u_int8_t      UDMA_cap; /* highest UDMA mode supported */
@@ -129,6 +130,9 @@ struct wdc_softc { /* Per controller state */
 
 	/* if WDC_CAPABILITY_MODE set in 'cap' */
 	void 		(*set_modes) __P((struct channel_softc *));
+
+	/* if WDC_CAPABILITY_IRQACK set in 'cap' */
+	void		(*irqack) __P((struct channel_softc *));
 };
 
  /*
diff --git a/sys/dev/scsipi/atapi_wdc.c b/sys/dev/scsipi/atapi_wdc.c
index ba6aa7ceb94b..505fed83f3d9 100644
--- a/sys/dev/scsipi/atapi_wdc.c
+++ b/sys/dev/scsipi/atapi_wdc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atapi_wdc.c,v 1.35 2000/05/15 08:48:25 bouyer Exp $	*/
+/*	$NetBSD: atapi_wdc.c,v 1.36 2000/06/12 21:10:40 bouyer Exp $	*/
 
 /*
  * Copyright (c) 1998 Manuel Bouyer.
@@ -467,6 +467,9 @@ wdc_atapi_intr(chp, xfer, irq)
 		wdc_atapi_reset(chp, xfer);
 		return 1;
 	}
+	if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+		chp->wdc->irqack(chp);
+
 	/* If we missed an IRQ and were using DMA, flag it as a DMA error */
 	if ((xfer->c_flags & C_TIMEOU) && (xfer->c_flags & C_DMA)) {
 		ata_dmaerr(drvp);
@@ -847,6 +850,8 @@ piomode:
 		errstring = "piomode";
 		if (wait_for_unbusy(chp, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & WDCS_ERR) {
 			if (drvp->PIO_mode < 3) {
 				drvp->PIO_mode = 3;
@@ -873,6 +878,8 @@ piomode:
 		errstring = "dmamode";
 		if (wait_for_unbusy(chp, delay))
 			goto timeout;
+		if (chp->wdc->cap & WDC_CAPABILITY_IRQACK)
+			chp->wdc->irqack(chp);
 		if (chp->ch_status & WDCS_ERR)
 			goto error;
 	/* fall through */