[PATCH] Re: LIBATA AHCI engine timeout hang with ATAPI devices

[Jeff Garzik <jgarzik@pobox.com>]

Eric A. Cottrell wrote:
> Hello,
>
> I made the mistake of getting the Plextor SATA DVD Recorder with my new 
> system not realizing that SATA support is just coming online.  I want to 
> turn this into an opportunity to make the Plextor work.  Thanks to the 
> IDE information pages I got a good start.
>
> I have success using the ata_piix and ahci drivers with SATA Hard 
> Drives.  I noticed that the Plextor works with the ata_piix driver  but 
> not with the AHCI driver.  The AHCI driver hangs after the INQUIRY is 
> printed.

You need something like the attached patch.

In general, ATAPI is still very much experimental at this point.  One 
known bug that affects libata is that ATAPI DMA is not aligned to a 
4-byte boundary.

	Jeff


# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2005/02/17 04:43:52-05:00 jgarzik@pobox.com 
#   [libata ahci] finish ATAPI support
# 
# drivers/scsi/ahci.c
#   2005/02/17 04:42:57-05:00 jgarzik@pobox.com +9 -13
#   [libata ahci] finish ATAPI support
# 
diff -Nru a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
--- a/drivers/scsi/ahci.c	2005-04-08 15:10:54 -04:00
+++ b/drivers/scsi/ahci.c	2005-04-08 15:10:54 -04:00
@@ -38,7 +38,7 @@
 #include <asm/io.h>
 
 #define DRV_NAME	"ahci"
-#define DRV_VERSION	"1.00"
+#define DRV_VERSION	"1.10"
 
 
 enum {
@@ -49,6 +49,7 @@
 	AHCI_CMD_SLOT_SZ	= 32 * 32,
 	AHCI_RX_FIS_SZ		= 256,
 	AHCI_CMD_TBL_HDR	= 0x80,
+	AHCI_CMD_TBL_CDB	= 0x40,
 	AHCI_CMD_TBL_SZ		= AHCI_CMD_TBL_HDR + (AHCI_MAX_SG * 16),
 	AHCI_PORT_PRIV_DMA_SZ	= AHCI_CMD_SLOT_SZ + AHCI_CMD_TBL_SZ +
 				  AHCI_RX_FIS_SZ,
@@ -477,7 +478,8 @@
 
 static void ahci_qc_prep(struct ata_queued_cmd *qc)
 {
-	struct ahci_port_priv *pp = qc->ap->private_data;
+	struct ata_port *ap = qc->ap;
+	struct ahci_port_priv *pp = ap->private_data;
 	u32 opts;
 	const u32 cmd_fis_len = 5; /* five dwords */
 
@@ -489,18 +491,8 @@
 	opts = (qc->n_elem << 16) | cmd_fis_len;
 	if (qc->tf.flags & ATA_TFLAG_WRITE)
 		opts |= AHCI_CMD_WRITE;
-
-	switch (qc->tf.protocol) {
-	case ATA_PROT_ATAPI:
-	case ATA_PROT_ATAPI_NODATA:
-	case ATA_PROT_ATAPI_DMA:
+	if (is_atapi_taskfile(&qc->tf))
 		opts |= AHCI_CMD_ATAPI;
-		break;
-
-	default:
-		/* do nothing */
-		break;
-	}
 
 	pp->cmd_slot[0].opts = cpu_to_le32(opts);
 	pp->cmd_slot[0].status = 0;
@@ -512,6 +504,10 @@
 	 * a SATA Register - Host to Device command FIS.
 	 */
 	ata_tf_to_fis(&qc->tf, pp->cmd_tbl, 0);
+	if (opts & AHCI_CMD_ATAPI) {
+		memset(pp->cmd_tbl + AHCI_CMD_TBL_CDB, 0, 32);
+		memcpy(pp->cmd_tbl + AHCI_CMD_TBL_CDB, qc->cdb, ap->cdb_len);
+	}
 
 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
 		return;