sata_inic162x: use IDMA for ATAPI commands

Use IDMA for ATAPI commands.  Write and some misc commands time out
when executed using ATAPI_PROT_DMA but ATAPI_PROT_PIO works fine.  As
PIO is driven by DMA too, it doesn't make any noticeable difference
for native SATA devices.  inic_check_atapi_dma() is implemented to
force PIO for those ATAPI commands.

After this change, sata_inic162x issues all commands using IDMA.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 47 insertions, 34 deletions

diff --git a/drivers/ata/sata_inic162x.c b/drivers/ata/sata_inic162x.c
index 579154c27902..cdae435620f6 100644
--- a/drivers/ata/sata_inic162x.c
+++ b/drivers/ata/sata_inic162x.c
@@ -192,7 +192,8 @@ struct inic_prd {
 
 struct inic_pkt {
         struct inic_cpb cpb;
-        struct inic_prd prd[LIBATA_MAX_PRD];
+        struct inic_prd prd[LIBATA_MAX_PRD + 1];        /* + 1 for cdb */
+        u8              cdb[ATAPI_CDB_LEN];
 } __packed;
 
 struct inic_host_priv {
@@ -361,23 +362,18 @@ static void inic_host_intr(struct ata_port *ap)
                 goto spurious;
         }
 
-        if (!ata_is_atapi(qc->tf.protocol)) {
-                if (likely(idma_stat & IDMA_STAT_DONE)) {
-                        inic_stop_idma(ap);
+        if (likely(idma_stat & IDMA_STAT_DONE)) {
+                inic_stop_idma(ap);
 
-                        /* Depending on circumstances, device error
-                         * isn't reported by IDMA, check it explicitly.
-                         */
-                        if (unlikely(readb(port_base + PORT_TF_COMMAND) &
-                                     (ATA_DF | ATA_ERR)))
-                                qc->err_mask |= AC_ERR_DEV;
+                /* Depending on circumstances, device error
+                 * isn't reported by IDMA, check it explicitly.
+                 */
+                if (unlikely(readb(port_base + PORT_TF_COMMAND) &
+                             (ATA_DF | ATA_ERR)))
+                        qc->err_mask |= AC_ERR_DEV;
 
-                        ata_qc_complete(qc);
-                        return;
-                }
-        } else {
-                if (likely(ata_sff_host_intr(ap, qc)))
-                        return;
+                ata_qc_complete(qc);
+                return;
         }
 
  spurious:
@@ -421,6 +417,19 @@ static irqreturn_t inic_interrupt(int irq, void *dev_instance)
         return IRQ_RETVAL(handled);
 }
 
+static int inic_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+        /* For some reason ATAPI_PROT_DMA doesn't work for some
+         * commands including writes and other misc ops.  Use PIO
+         * protocol instead, which BTW is driven by the DMA engine
+         * anyway, so it shouldn't make much difference for native
+         * SATA devices.
+         */
+        if (atapi_cmd_type(qc->cdb[0]) == READ)
+                return 0;
+        return 1;
+}
+
 static void inic_fill_sg(struct inic_prd *prd, struct ata_queued_cmd *qc)
 {
         struct scatterlist *sg;
@@ -452,20 +461,21 @@ static void inic_qc_prep(struct ata_queued_cmd *qc)
         struct inic_prd *prd = pkt->prd;
         bool is_atapi = ata_is_atapi(qc->tf.protocol);
         bool is_data = ata_is_data(qc->tf.protocol);
+        unsigned int cdb_len = 0;
 
         VPRINTK("ENTER\n");
 
         if (is_atapi)
-                return;
+                cdb_len = qc->dev->cdb_len;
 
         /* prepare packet, based on initio driver */
         memset(pkt, 0, sizeof(struct inic_pkt));
 
         cpb->ctl_flags = CPB_CTL_VALID | CPB_CTL_IEN;
-        if (is_data)
+        if (is_atapi || is_data)
                 cpb->ctl_flags |= CPB_CTL_DATA;
 
-        cpb->len = cpu_to_le32(qc->nbytes);
+        cpb->len = cpu_to_le32(qc->nbytes + cdb_len);
         cpb->prd = cpu_to_le32(pp->pkt_dma + offsetof(struct inic_pkt, prd));
 
         cpb->device = qc->tf.device;
@@ -486,6 +496,18 @@ static void inic_qc_prep(struct ata_queued_cmd *qc)
         cpb->command = qc->tf.command;
         /* don't load ctl - dunno why.  it's like that in the initio driver */
 
+        /* setup PRD for CDB */
+        if (is_atapi) {
+                memcpy(pkt->cdb, qc->cdb, ATAPI_CDB_LEN);
+                prd->mad = cpu_to_le32(pp->pkt_dma +
+                                       offsetof(struct inic_pkt, cdb));
+                prd->len = cpu_to_le16(cdb_len);
+                prd->flags = PRD_CDB | PRD_WRITE;
+                if (!is_data)
+                        prd->flags |= PRD_END;
+                prd++;
+        }
+
         /* setup sg table */
         if (is_data)
                 inic_fill_sg(prd, qc);
@@ -498,16 +520,12 @@ static unsigned int inic_qc_issue(struct ata_queued_cmd *qc)
         struct ata_port *ap = qc->ap;
         void __iomem *port_base = inic_port_base(ap);
 
-        if (!ata_is_atapi(qc->tf.protocol)) {
-                /* fire up the ADMA engine */
-                writew(HCTL_FTHD0, port_base + HOST_CTL);
-                writew(IDMA_CTL_GO, port_base + PORT_IDMA_CTL);
-                writeb(0, port_base + PORT_CPB_PTQFIFO);
-
-                return 0;
-        }
+        /* fire up the ADMA engine */
+        writew(HCTL_FTHD0, port_base + HOST_CTL);
+        writew(IDMA_CTL_GO, port_base + PORT_IDMA_CTL);
+        writeb(0, port_base + PORT_CPB_PTQFIFO);
 
-        return ata_sff_qc_issue(qc);
+        return 0;
 }
 
 static void inic_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
@@ -698,6 +716,7 @@ static int inic_port_start(struct ata_port *ap)
 static struct ata_port_operations inic_port_ops = {
         .inherits               = &ata_sff_port_ops,
 
+        .check_atapi_dma        = inic_check_atapi_dma,
         .qc_prep                = inic_qc_prep,
         .qc_issue               = inic_qc_issue,
         .qc_fill_rtf            = inic_qc_fill_rtf,
@@ -717,12 +736,6 @@ static struct ata_port_operations inic_port_ops = {
 };
 
 static struct ata_port_info inic_port_info = {
-        /* For some reason, ATAPI_PROT_PIO is broken on this
-         * controller, and no, PIO_POLLING does't fix it.  It somehow
-         * manages to report the wrong ireason and ignoring ireason
-         * results in machine lock up.  Tell libata to always prefer
-         * DMA.
-         */
         .flags                  = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA,
         .pio_mask               = 0x1f, /* pio0-4 */
         .mwdma_mask             = 0x07, /* mwdma0-2 */