1 files changed, 66 insertions, 3 deletions

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 72ebab0bc75..a878f4734f8 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -128,6 +128,7 @@ int ide_build_sglist(ide_drive_t *drive, struct request *rq)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	struct scatterlist *sg = hwif->sg_table;
+	int i;
 
 	ide_map_sg(drive, rq);
 
@@ -136,8 +137,13 @@ int ide_build_sglist(ide_drive_t *drive, struct request *rq)
 	else
 		hwif->sg_dma_direction = DMA_TO_DEVICE;
 
-	return dma_map_sg(hwif->dev, sg, hwif->sg_nents,
-			  hwif->sg_dma_direction);
+	i = dma_map_sg(hwif->dev, sg, hwif->sg_nents, hwif->sg_dma_direction);
+	if (i) {
+		hwif->orig_sg_nents = hwif->sg_nents;
+		hwif->sg_nents = i;
+	}
+
+	return i;
 }
 EXPORT_SYMBOL_GPL(ide_build_sglist);
 
@@ -156,7 +162,7 @@ void ide_destroy_dmatable(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
 
-	dma_unmap_sg(hwif->dev, hwif->sg_table, hwif->sg_nents,
+	dma_unmap_sg(hwif->dev, hwif->sg_table, hwif->orig_sg_nents,
 		     hwif->sg_dma_direction);
 }
 EXPORT_SYMBOL_GPL(ide_destroy_dmatable);
@@ -464,6 +470,63 @@ void ide_dma_timeout(ide_drive_t *drive)
 }
 EXPORT_SYMBOL_GPL(ide_dma_timeout);
 
+/*
+ * un-busy the port etc, and clear any pending DMA status. we want to
+ * retry the current request in pio mode instead of risking tossing it
+ * all away
+ */
+ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	struct request *rq;
+	ide_startstop_t ret = ide_stopped;
+
+	/*
+	 * end current dma transaction
+	 */
+
+	if (error < 0) {
+		printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
+		(void)hwif->dma_ops->dma_end(drive);
+		ret = ide_error(drive, "dma timeout error",
+				hwif->tp_ops->read_status(hwif));
+	} else {
+		printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
+		hwif->dma_ops->dma_timeout(drive);
+	}
+
+	/*
+	 * disable dma for now, but remember that we did so because of
+	 * a timeout -- we'll reenable after we finish this next request
+	 * (or rather the first chunk of it) in pio.
+	 */
+	drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY;
+	drive->retry_pio++;
+	ide_dma_off_quietly(drive);
+
+	/*
+	 * un-busy drive etc and make sure request is sane
+	 */
+
+	rq = hwif->rq;
+	if (!rq)
+		goto out;
+
+	hwif->rq = NULL;
+
+	rq->errors = 0;
+
+	if (!rq->bio)
+		goto out;
+
+	rq->sector = rq->bio->bi_sector;
+	rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
+	rq->hard_cur_sectors = rq->current_nr_sectors;
+	rq->buffer = bio_data(rq->bio);
+out:
+	return ret;
+}
+
 void ide_release_dma_engine(ide_hwif_t *hwif)
 {
 	if (hwif->dmatable_cpu) {