ide-atapi: split drive-specific functionality in ide_issue_pc

There should be no functionality change resulting from this patch.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-atapi.c

@@ -564,39 +564,43 @@ static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
 
 ide_startstop_t ide_issue_pc(ide_drive_t *drive, unsigned int timeout)
 {
-	struct ide_atapi_pc *pc = drive->pc;
+	struct ide_atapi_pc *pc;
 	ide_hwif_t *hwif = drive->hwif;
 	ide_expiry_t *expiry = NULL;
 	u32 tf_flags;
 	u16 bcount;
 
-	/* We haven't transferred any data yet */
-	pc->xferred = 0;
-	pc->cur_pos = pc->buf;
-
 	if (dev_is_idecd(drive)) {
 		tf_flags = IDE_TFLAG_OUT_NSECT | IDE_TFLAG_OUT_LBAL;
 		bcount = ide_cd_get_xferlen(hwif->hwgroup->rq);
 		expiry = ide_cd_expiry;
+
+		if (drive->dma)
+			drive->dma = !hwif->dma_ops->dma_setup(drive);
 	} else {
+		pc = drive->pc;
+
+		/* We haven't transferred any data yet */
+		pc->xferred = 0;
+		pc->cur_pos = pc->buf;
+
 		tf_flags = IDE_TFLAG_OUT_DEVICE;
 		bcount = ((drive->media == ide_tape) ?
 				pc->req_xfer :
 				min(pc->req_xfer, 63 * 1024));
-	}
 
-	if (pc->flags & PC_FLAG_DMA_ERROR) {
-		pc->flags &= ~PC_FLAG_DMA_ERROR;
-		ide_dma_off(drive);
-	}
+		if (pc->flags & PC_FLAG_DMA_ERROR) {
+			pc->flags &= ~PC_FLAG_DMA_ERROR;
+			ide_dma_off(drive);
+		}
 
-	if (((pc->flags & PC_FLAG_DMA_OK) &&
-		(drive->dev_flags & IDE_DFLAG_USING_DMA)) ||
-	    drive->dma)
-		drive->dma = !hwif->dma_ops->dma_setup(drive);
+		if ((pc->flags & PC_FLAG_DMA_OK) &&
+		     (drive->dev_flags & IDE_DFLAG_USING_DMA))
+			drive->dma = !hwif->dma_ops->dma_setup(drive);
 
-	if (!drive->dma)
-		pc->flags &= ~PC_FLAG_DMA_OK;
+		if (!drive->dma)
+			pc->flags &= ~PC_FLAG_DMA_OK;
+	}
 
 	ide_pktcmd_tf_load(drive, tf_flags, bcount, drive->dma);