ide-scsi driver starts DMA too soon

@@ -397,6 +397,8 @@
 	idescsi_pc_t *pc = scsi->pc;
 	byte ireason;
 	ide_startstop_t startstop;
+	struct request *rq = pc->rq;
+	int dma_ok = 0;
 
 	if (ide_wait_stat (&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
 		printk (KERN_ERR "ide-scsi: Strange, packet command initiated yet DRQ isn't asserted\n");

@@ -407,8 +409,14 @@
 		printk (KERN_ERR "ide-scsi: (IO,CoD) != (0,1) while issuing a packet command\n");
 		return ide_do_reset (drive);
 	}
+	if (drive->using_dma && rq->bh)
+		dma_ok=!HWIF(drive)->dmaproc(test_bit (PC_WRITING, &pc->flags) ? ide_dma_write : ide_dma_read, drive);
 	ide_set_handler(drive, &idescsi_pc_intr, get_timeout(pc), NULL);	/* Set the interrupt routine */
 	atapi_output_bytes (drive, scsi->pc->c, 12);			/* Send the actual packet */
+	if (dma_ok) {
+		set_bit (PC_DMA_IN_PROGRESS, &pc->flags);
+		(void) (HWIF(drive)->dmaproc(ide_dma_begin, drive));
+	}
 	return ide_started;
 }
 

@@ -437,10 +445,6 @@
 	OUT_BYTE (bcount >> 8,IDE_BCOUNTH_REG);
 	OUT_BYTE (bcount & 0xff,IDE_BCOUNTL_REG);
 
-	if (dma_ok) {
-		set_bit (PC_DMA_IN_PROGRESS, &pc->flags);
-		(void) (HWIF(drive)->dmaproc(ide_dma_begin, drive));
-	}
 	if (test_bit (IDESCSI_DRQ_INTERRUPT, &scsi->flags)) {
 		ide_set_handler (drive, &idescsi_transfer_pc, get_timeout(pc), NULL);
 		OUT_BYTE (WIN_PACKETCMD, IDE_COMMAND_REG);		/* Issue the packet command */