bugfixes from netbsd ata_wdc.c, ok csapuntz@

from bouyer:
- Add some debug printf (WDCPROBE) in _wdcreset_wait(), I've needed these
  2 times in the past
- Set up timeout per xfer instead of per interrupt. This helps with
  PIO transfer (we would call timeout()/untimout() several times for a
  transfer).
- If we missed an interrupt for a PIO transfer, reset and restart it
  immedialy, don't try to recover and continue. If we missed an interrupt we
  may have lost a read/write cycle on the IDE bus. If this happens 1) we
  corrupt data and 2) we enter an interrupt loop at the end of the xfer, as
  the drive has some more data to read/write, but the host thinks the xfer is
  done.
This last change fix the (or at last some of the) 'lookup after lost interrupt'
some peoples have been experiencing.

1 files changed, 37 insertions, 16 deletions

diff --git a/sys/dev/ata/ata_wdc.c b/sys/dev/ata/ata_wdc.c
index 412a04ef898..51c1f4711f2 100644
--- a/sys/dev/ata/ata_wdc.c
+++ b/sys/dev/ata/ata_wdc.c
@@ -1,5 +1,4 @@
-/*      $OpenBSD: ata_wdc.c,v 1.1 1999/07/18 21:25:17 csapuntz Exp $     */
-/*	$NetBSD: ata_wdc.c,v 1.19 1999/04/01 21:46:28 bouyer Exp $	*/
+/*	$NetBSD: ata_wdc.c,v 1.21 1999/08/09 09:43:11 bouyer Exp $	*/
 
 /*
  * Copyright (c) 1998 Manuel Bouyer.
@@ -124,6 +123,7 @@ struct cfdriver wdc_cd = {
 #endif
 
 void  wdc_ata_bio_start  __P((struct channel_softc *,struct wdc_xfer *));
+void  _wdc_ata_bio_start  __P((struct channel_softc *,struct wdc_xfer *));
 int   wdc_ata_bio_intr   __P((struct channel_softc *, struct wdc_xfer *, int));
 void  wdc_ata_bio_done   __P((struct channel_softc *, struct wdc_xfer *)); 
 int   wdc_ata_ctrl_intr __P((struct channel_softc *, struct wdc_xfer *, int));
@@ -168,6 +168,22 @@ wdc_ata_bio_start(chp, xfer)
 	struct wdc_xfer *xfer;
 {
 	struct ata_bio *ata_bio = xfer->cmd;
+	WDCDEBUG_PRINT(("wdc_ata_bio_start %s:%d:%d\n",
+	    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive),
+	    DEBUG_XFERS);
+
+	/* start timeout machinery */
+	if ((ata_bio->flags & ATA_POLL) == 0)
+		timeout(wdctimeout, chp, ATA_DELAY / 1000 * hz);
+	_wdc_ata_bio_start(chp, xfer);
+}
+
+void
+_wdc_ata_bio_start(chp, xfer)
+	struct channel_softc *chp;
+	struct wdc_xfer *xfer;
+{
+	struct ata_bio *ata_bio = xfer->cmd;
 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
 	u_int16_t cyl;
 	u_int8_t head, sect, cmd = 0;
@@ -175,10 +191,9 @@ wdc_ata_bio_start(chp, xfer)
 	int ata_delay;
 	int dma_flags = 0;
 
-	WDCDEBUG_PRINT(("wdc_ata_bio_start %s:%d:%d\n",
+	WDCDEBUG_PRINT(("_wdc_ata_bio_start %s:%d:%d\n",
 	    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive),
-	    DEBUG_XFERS);
-
+	    DEBUG_INTR | DEBUG_XFERS);
 	/* Do control operations specially. */
 	if (drvp->state < READY) {
 		/*
@@ -188,10 +203,10 @@ wdc_ata_bio_start(chp, xfer)
 		 */
 		/* at this point, we should only be in RECAL state */
 		if (drvp->state != RECAL) {
-			printf("%s:%d:%d: bad state %d in wdc_ata_bio_start\n",
+			printf("%s:%d:%d: bad state %d in _wdc_ata_bio_start\n",
 			    chp->wdc->sc_dev.dv_xname, chp->channel,
 			    xfer->drive, drvp->state);
-			panic("wdc_ata_bio_start: bad state");
+			panic("_wdc_ata_bio_start: bad state");
 		}
 		xfer->c_intr = wdc_ata_ctrl_intr;
 		bus_space_write_1(chp->cmd_iot, chp->cmd_ioh, wd_sdh,
@@ -202,8 +217,6 @@ wdc_ata_bio_start(chp, xfer)
 		drvp->state = RECAL_WAIT;
 		if ((ata_bio->flags & ATA_POLL) == 0) {
 			chp->ch_flags |= WDCF_IRQ_WAIT;
-			timeout(wdctimeout, chp,
-			    ATA_DELAY / 1000 * hz);
 		} else {
 			/* Wait for at last 400ns for status bit to be valid */
 			DELAY(1);
@@ -375,7 +388,6 @@ again:
 intr:	/* Wait for IRQ (either real or polled) */
 	if ((ata_bio->flags & ATA_POLL) == 0) {
 		chp->ch_flags |= WDCF_IRQ_WAIT;
-		timeout(wdctimeout, chp, ata_delay / 1000 * hz);
 	} else {
 		/* Wait for at last 400ns for status bit to be valid */
 		delay(1);
@@ -423,6 +435,16 @@ wdc_ata_bio_intr(chp, xfer, irq)
 		dma_flags |= (ata_bio->flags & ATA_POLL) ?  WDC_DMA_POLL : 0;
 	}
 
+	/*
+	 * if we missed an interrupt in a PIO transfer, reset and restart.
+	 * Don't try to continue transfer, we may have missed cycles.
+	 */
+	if ((xfer->c_flags & (C_TIMEOU | C_DMA)) == C_TIMEOU) {
+		ata_bio->error = TIMEOUT;
+		wdc_ata_bio_done(chp, xfer);
+		return 1;
+	}
+
 	/* Ack interrupt done by wait_for_unbusy */
 	if (wait_for_unbusy(chp,
 	    (irq == 0) ? ATA_DELAY : 0) < 0) {
@@ -539,9 +561,9 @@ end:
 	if (xfer->c_bcount > 0) {
 		if ((ata_bio->flags & ATA_POLL) == 0) {
 			/* Start the next operation */
-			wdc_ata_bio_start(chp, xfer);
+			_wdc_ata_bio_start(chp, xfer);
 		} else {
-			/* Let wdc_ata_bio_start do the loop */
+			/* Let _wdc_ata_bio_start do the loop */
 			return 1;
 		}
 	} else { /* Done with this transfer */
@@ -557,7 +579,6 @@ wdc_ata_bio_done(chp, xfer)
 	struct wdc_xfer *xfer;
 {
 	struct ata_bio *ata_bio = xfer->cmd;
-	int need_done = xfer->c_flags & C_NEEDDONE;
 	int drive = xfer->drive;
 	struct ata_drive_datas *drvp = &chp->ch_drive[drive];
 
@@ -566,6 +587,7 @@ wdc_ata_bio_done(chp, xfer)
 	    (u_int)xfer->c_flags),
 	    DEBUG_XFERS);
 
+	untimeout(wdctimeout, chp);
 	if (ata_bio->error == NOERROR)
 		drvp->n_dmaerrs = 0;
 	else if (drvp->n_dmaerrs >= NERRS_MAX) {
@@ -579,7 +601,7 @@ wdc_ata_bio_done(chp, xfer)
 	wdc_free_xfer(chp, xfer);
 
 	ata_bio->flags |= ATA_ITSDONE;
-	if (need_done) {
+	if ((ata_bio->flags & ATA_POLL) == 0) {
 		WDCDEBUG_PRINT(("wdc_ata_done: wddone\n"), DEBUG_XFERS);
 		wddone(chp->ch_drive[drive].drv_softc);
 	}
@@ -703,13 +725,12 @@ again:
 		 * The drive is usable now
 		 */
 		xfer->c_intr = wdc_ata_bio_intr;
-		wdc_ata_bio_start(chp, xfer); 
+		_wdc_ata_bio_start(chp, xfer); 
 		return 1;
 	}
 
 	if ((ata_bio->flags & ATA_POLL) == 0) {
 		chp->ch_flags |= WDCF_IRQ_WAIT;
-		timeout(wdctimeout, chp, ATA_DELAY / 1000 * hz);
 	} else {
 		goto again;
 	}