sata_mv clean up mv_stop_edma usage

Clean up uses of mv_stop_edma{_engine}() to match datasheet requirements.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index ee6ca97c454511044d628542c536c1f2a84e4665..5b9f937d0f87e2acce89ca88b894429edec83493 100644 (file)
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -517,7 +517,7 @@ static void mv_reset_pci_bus(struct ata_host *host, void __iomem *mmio);
 static void mv_reset_channel(struct mv_host_priv *hpriv, void __iomem *mmio,
                             unsigned int port_no);
 static int mv_stop_edma(struct ata_port *ap);
-static int mv_stop_edma_engine(struct ata_port *ap);
+static int mv_stop_edma_engine(void __iomem *port_mmio);
 static void mv_edma_cfg(struct ata_port *ap, int want_ncq);
 
 /* .sg_tablesize is (MV_MAX_SG_CT / 2) in the structures below
@@ -805,7 +805,7 @@ static void mv_start_dma(struct ata_port *ap, void __iomem *port_mmio,
        if (pp->pp_flags & MV_PP_FLAG_EDMA_EN) {
                int using_ncq = ((pp->pp_flags & MV_PP_FLAG_NCQ_EN) != 0);
                if (want_ncq != using_ncq)
-                       mv_stop_edma_engine(ap);
+                       mv_stop_edma(ap);
        }
        if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN)) {
                struct mv_host_priv *hpriv = ap->host->private_data;
@@ -841,57 +841,41 @@ static void mv_start_dma(struct ata_port *ap, void __iomem *port_mmio,
 
 /**
  *      mv_stop_edma_engine - Disable eDMA engine
- *      @ap: ATA channel to manipulate
- *
- *      Verify the local cache of the eDMA state is accurate with a
- *      WARN_ON.
+ *      @port_mmio: io base address
  *
  *      LOCKING:
  *      Inherited from caller.
  */
-static int mv_stop_edma_engine(struct ata_port *ap)
+static int mv_stop_edma_engine(void __iomem *port_mmio)
 {
-       void __iomem *port_mmio = mv_ap_base(ap);
-       struct mv_port_priv *pp = ap->private_data;
-       u32 reg;
-       int i, err = 0;
+       int i;
 
-       if (pp->pp_flags & MV_PP_FLAG_EDMA_EN) {
-               /* Disable EDMA if active.   The disable bit auto clears.
-                */
-               writelfl(EDMA_DS, port_mmio + EDMA_CMD_OFS);
-               pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
-       } else {
-               WARN_ON(EDMA_EN & readl(port_mmio + EDMA_CMD_OFS));
-       }
+       /* Disable eDMA.  The disable bit auto clears. */
+       writelfl(EDMA_DS, port_mmio + EDMA_CMD_OFS);
 
-       /* now properly wait for the eDMA to stop */
-       for (i = 1000; i > 0; i--) {
-               reg = readl(port_mmio + EDMA_CMD_OFS);
+       /* Wait for the chip to confirm eDMA is off. */
+       for (i = 10000; i > 0; i--) {
+               u32 reg = readl(port_mmio + EDMA_CMD_OFS);
                if (!(reg & EDMA_EN))
-                       break;
-
-               udelay(100);
-       }
-
-       if (reg & EDMA_EN) {
-               ata_port_printk(ap, KERN_ERR, "Unable to stop eDMA\n");
-               err = -EIO;
+                       return 0;
+               udelay(10);
        }
-
-       return err;
+       return -EIO;
 }
 
 static int mv_stop_edma(struct ata_port *ap)
 {
-       unsigned long flags;
-       int rc;
-
-       spin_lock_irqsave(&ap->host->lock, flags);
-       rc = mv_stop_edma_engine(ap);
-       spin_unlock_irqrestore(&ap->host->lock, flags);
+       void __iomem *port_mmio = mv_ap_base(ap);
+       struct mv_port_priv *pp = ap->private_data;
 
-       return rc;
+       if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN))
+               return 0;
+       pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
+       if (mv_stop_edma_engine(port_mmio)) {
+               ata_port_printk(ap, KERN_ERR, "Unable to stop eDMA\n");
+               return -EIO;
+       }
+       return 0;
 }
 
 #ifdef ATA_DEBUG
@@ -1401,7 +1385,7 @@ static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)
                 * port.  Turn off EDMA so there won't be problems accessing
                 * shadow block, etc registers.
                 */
-               mv_stop_edma_engine(ap);
+               mv_stop_edma(ap);
                return ata_qc_issue_prot(qc);
        }
 
@@ -1915,8 +1899,12 @@ static void mv5_reset_hc_port(struct mv_host_priv *hpriv, void __iomem *mmio,
 {
        void __iomem *port_mmio = mv_port_base(mmio, port);
 
-       writelfl(EDMA_DS, port_mmio + EDMA_CMD_OFS);
-
+       /*
+        * The datasheet warns against setting ATA_RST when EDMA is active
+        * (but doesn't say what the problem might be).  So we first try
+        * to disable the EDMA engine before doing the ATA_RST operation.
+        */
+       mv_stop_edma_engine(port_mmio);
        mv_reset_channel(hpriv, mmio, port);
 
        ZERO(0x028);    /* command */
@@ -2191,8 +2179,12 @@ static void mv_soc_reset_hc_port(struct mv_host_priv *hpriv,
 {
        void __iomem *port_mmio = mv_port_base(mmio, port);
 
-       writelfl(EDMA_DS, port_mmio + EDMA_CMD_OFS);
-
+       /*
+        * The datasheet warns against setting ATA_RST when EDMA is active
+        * (but doesn't say what the problem might be).  So we first try
+        * to disable the EDMA engine before doing the ATA_RST operation.
+        */
+       mv_stop_edma_engine(port_mmio);
        mv_reset_channel(hpriv, mmio, port);
 
        ZERO(0x028);            /* command */
@@ -2250,6 +2242,10 @@ static void mv_soc_reset_bus(struct ata_host *host, void __iomem *mmio)
        return;
 }
 
+/*
+ * Caller must ensure that EDMA is not active,
+ * by first doing mv_stop_edma() where needed.
+ */
 static void mv_reset_channel(struct mv_host_priv *hpriv, void __iomem *mmio,
                             unsigned int port_no)
 {
@@ -2392,10 +2388,11 @@ static int mv_hardreset(struct ata_link *link, unsigned int *class,
 {
        struct ata_port *ap = link->ap;
        struct mv_host_priv *hpriv = ap->host->private_data;
+       struct mv_port_priv *pp = ap->private_data;
        void __iomem *mmio = hpriv->base;
 
-       mv_stop_edma(ap);
        mv_reset_channel(hpriv, mmio, ap->port_no);
+       pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
        mv_phy_reset(ap, class, deadline);
 
        return 0;