diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 72ebab0bc755571c0735b87aed3574a72db12eec..059c90bb5ad2f4082c52ad695100ea83490c0263 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);
diff --git a/include/linux/ide.h b/include/linux/ide.h
index e0cedfe9fad46b63d13fad9ce0a006d5e75fecd3..25087aead65768401a8b32b582fd42780401fde1 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -797,6 +797,7 @@ typedef struct hwif_s {
 	struct scatterlist *sg_table;
 	int sg_max_nents;		/* Maximum number of entries in it */
 	int sg_nents;			/* Current number of entries in it */
+	int orig_sg_nents;
 	int sg_dma_direction;		/* dma transfer direction */
 
 	/* data phase of the active command (currently only valid for PIO/DMA) */