From b562468cc3bd0c81decba1f5f39a7173f839e57e Mon Sep 17 00:00:00 2001
From: Mark Lord <liml@rtr.ca>
Date: Mon, 31 Mar 2008 19:34:40 -0400
Subject: 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>
---
drivers/ata/sata_mv.c | 87 +++++++++++++++++++++++++--------------------------
1 file changed, 42 insertions(+), 45 deletions(-)
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index ee6ca97c454..5b9f937d0f8 100644
--- 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;
--
cgit v1.2.3-18-g5258