[PATCH] 2.5.8 IDE 40 - Make the ide-cd driver usable again in DMA mode by adapting it to the TCQ related request handling changes and fixing some other minor stuff related to this. This patch is ugly like hell I know. Cleanup will follow separately. It was hard enough to make this going agian at all.

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 2aebf92..29e0be7 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c

@@ -535,9 +535,9 @@
 
 	/* stuff the sense request in front of our current request */
 	rq = &info->request_sense_request;
+	ide_init_drive_cmd(rq);
 	rq->cmd[0] = GPCMD_REQUEST_SENSE;
 	rq->cmd[4] = pc->buflen;
-	ide_init_drive_cmd(rq);
 	rq->flags = REQ_SENSE;
 
 	/* FIXME --mdcki */
@@ -558,8 +558,10 @@
 	if ((rq->flags & REQ_CMD) && !rq->current_nr_sectors)
 		uptodate = 1;
 
+#if 0
 	/* FIXME --mdcki */
 	HWGROUP(drive)->rq->special = NULL;
+#endif
 	ide_end_request(drive, uptodate);
 }
 
@@ -1215,13 +1217,22 @@
 /*
  * Start a read request from the CD-ROM.
  */
-static ide_startstop_t cdrom_start_read (ide_drive_t *drive, unsigned int block)
+static ide_startstop_t cdrom_start_read(struct ata_device *drive, struct ata_request *ar, unsigned int block)
 {
 	struct cdrom_info *info = drive->driver_data;
-	struct request *rq = HWGROUP(drive)->rq;
+	struct request *rq = ar->ar_rq;
+
+	if (ar->ar_flags & ATA_AR_QUEUED) {
+//		spin_lock_irqsave(DRIVE_LOCK(drive), flags);
+		blkdev_dequeue_request(rq);
+//		spin_unlock_irqrestore(DRIVE_LOCK(drive), flags);
+	}
+
 
 	restore_request(rq);
 
+	rq->special = ar;
+
 	/* Satisfy whatever we can of this request from our cached sector. */
 	if (cdrom_read_from_buffer(drive))
 		return ide_stopped;
@@ -1404,10 +1415,10 @@
 	struct request rq;
 	int retries = 10;
 
-	memcpy(rq.cmd, cmd, CDROM_PACKET_SIZE);
 	/* Start of retry loop. */
 	do {
 		ide_init_drive_cmd(&rq);
+		memcpy(rq.cmd, cmd, CDROM_PACKET_SIZE);
 
 		rq.flags = REQ_PC;
 
@@ -1630,12 +1641,14 @@
  * cdrom driver request routine.
  */
 static ide_startstop_t
-ide_do_rw_cdrom(ide_drive_t *drive, struct request *rq, unsigned long block)
+ide_cdrom_do_request(struct ata_device *drive, struct request *rq, sector_t block)
 {
 	ide_startstop_t action;
 	struct cdrom_info *info = drive->driver_data;
 
 	if (rq->flags & REQ_CMD) {
+	
+
 		if (CDROM_CONFIG_FLAGS(drive)->seeking) {
 			unsigned long elpased = jiffies - info->start_seek;
 			int stat = GET_STAT();
@@ -1652,8 +1665,30 @@
 		if (IDE_LARGE_SEEK(info->last_block, block, IDECD_SEEK_THRESHOLD) && drive->dsc_overlap)
 			action = cdrom_start_seek (drive, block);
 		else {
+			unsigned long flags;
+			struct ata_request *ar;
+
+			/*
+			 * get a new command (push ar further down to avoid grabbing lock here
+			 */
+			spin_lock_irqsave(DRIVE_LOCK(drive), flags);
+
+			ar = ata_ar_get(drive);
+
+			/*
+			 * we've reached maximum queue depth, bail
+			 */
+			if (!ar) {
+				spin_unlock_irqrestore(DRIVE_LOCK(drive), flags);
+
+				return ide_started;
+			}
+
+			ar->ar_rq = rq;
+			spin_unlock_irqrestore(DRIVE_LOCK(drive), flags);
+
 			if (rq_data_dir(rq) == READ)
-				action = cdrom_start_read(drive, block);
+				action = cdrom_start_read(drive, ar, block);
 			else
 				action = cdrom_start_write(drive, rq);
 		}
@@ -2297,7 +2332,7 @@
 	struct request req;
 	int ret;
 
-	ide_init_drive_cmd (&req);
+	ide_init_drive_cmd(&req);
 	req.flags = REQ_SPECIAL;
 	ret = ide_do_drive_cmd(drive, &req, ide_wait);
 
@@ -2927,7 +2962,7 @@
 	owner:			THIS_MODULE,
 	cleanup:		ide_cdrom_cleanup,
 	standby:		NULL,
-	do_request:		ide_do_rw_cdrom,
+	do_request:		ide_cdrom_do_request,
 	end_request:		NULL,
 	ioctl:			ide_cdrom_ioctl,
 	open:			ide_cdrom_open,

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index e828e6c..8f25d62 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c

@@ -549,8 +549,11 @@
 	/* This can happen with drivers abusing the special request field.
 	 */
 
-	if (!ar)
+	if (!ar) {
+		printk(KERN_ERR "DMA without ATA request\n");
+
 		return 1;
+	}
 
 	if (rq_data_dir(ar->ar_rq) == READ)
 		reading = 1 << 3;

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 3bfe703..b7dbb28 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c

@@ -168,6 +168,9 @@
 		}
 		printk (" drive\n");
 		drive->type = type;
+
+		goto init_queue;
+
 		return;
 	}
 
@@ -198,6 +201,7 @@
 	if (drive->channel->quirkproc)
 		drive->quirk_list = drive->channel->quirkproc(drive);
 
+init_queue:
 	/*
 	 * it's an ata drive, build command list
 	 */