pata_hpt366: reimplement mode programming

Reimplement mode programming logic of pata_hpt366 such that it's
identical to that of IDE hpt366 driver.  The differences were...

* pata_hpt366 used 0xCFFF8FFFF to mask pio modes and 0x3FFFFFFF dma
  modes.  IDE hpt366 uses 0xC1F8FFFF for PIO, 0x303800FF for MWDMA and
  0x30070000 for UDMA.

* pata_hpt366 doesn't set 0x08000000 for PIO unless it's already set
  and always turns it on for MWDMA/UDMA.  IDE hpt366 doesn't bother
  with the bit.  It always uses what was there.

* IDE hpt366 always clears 0xC0000000.  pata_hpt366 doesn't.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 44 insertions, 65 deletions

diff --git a/drivers/ata/pata_hpt366.c b/drivers/ata/pata_hpt366.c
index e0c4f05d7d57..65c28e5a6cd7 100644
--- a/drivers/ata/pata_hpt366.c
+++ b/drivers/ata/pata_hpt366.c
@@ -30,7 +30,7 @@
 #define DRV_VERSION     "0.6.2"
 
 struct hpt_clock {
-        u8      xfer_speed;
+        u8      xfer_mode;
         u32     timing;
 };
 
@@ -189,28 +189,6 @@ static unsigned long hpt366_filter(struct ata_device *adev, unsigned long mask)
         return ata_bmdma_mode_filter(adev, mask);
 }
 
-/**
- *      hpt36x_find_mode        -       reset the hpt36x bus
- *      @ap: ATA port
- *      @speed: transfer mode
- *
- *      Return the 32bit register programming information for this channel
- *      that matches the speed provided.
- */
-
-static u32 hpt36x_find_mode(struct ata_port *ap, int speed)
-{
-        struct hpt_clock *clocks = ap->host->private_data;
-
-        while(clocks->xfer_speed) {
-                if (clocks->xfer_speed == speed)
-                        return clocks->timing;
-                clocks++;
-        }
-        BUG();
-        return 0xffffffffU;     /* silence compiler warning */
-}
-
 static int hpt36x_cable_detect(struct ata_port *ap)
 {
         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
@@ -226,25 +204,16 @@ static int hpt36x_cable_detect(struct ata_port *ap)
         return ATA_CBL_PATA80;
 }
 
-/**
- *      hpt366_set_piomode              -       PIO setup
- *      @ap: ATA interface
- *      @adev: device on the interface
- *
- *      Perform PIO mode setup.
- */
-
-static void hpt366_set_piomode(struct ata_port *ap, struct ata_device *adev)
+static void hpt366_set_mode(struct ata_port *ap, struct ata_device *adev,
+                            u8 mode)
 {
+        struct hpt_clock *clocks = ap->host->private_data;
         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-        u32 addr1, addr2;
-        u32 reg;
-        u32 mode;
+        u32 addr1 = 0x40 + 4 * (adev->devno + 2 * ap->port_no);
+        u32 addr2 = 0x51 + 4 * ap->port_no;
+        u32 mask, reg;
         u8 fast;
 
-        addr1 = 0x40 + 4 * (adev->devno + 2 * ap->port_no);
-        addr2 = 0x51 + 4 * ap->port_no;
-
         /* Fast interrupt prediction disable, hold off interrupt disable */
         pci_read_config_byte(pdev, addr2, &fast);
         if (fast & 0x80) {
@@ -252,12 +221,43 @@ static void hpt366_set_piomode(struct ata_port *ap, struct ata_device *adev)
                 pci_write_config_byte(pdev, addr2, fast);
         }
 
+        /* determine timing mask and find matching clock entry */
+        if (mode < XFER_MW_DMA_0)
+                mask = 0xc1f8ffff;
+        else if (mode < XFER_UDMA_0)
+                mask = 0x303800ff;
+        else
+                mask = 0x30070000;
+
+        while (clocks->xfer_mode) {
+                if (clocks->xfer_mode == mode)
+                        break;
+                clocks++;
+        }
+        if (!clocks->xfer_mode)
+                BUG();
+
+        /*
+         * Combine new mode bits with old config bits and disable
+         * on-chip PIO FIFO/buffer (and PIO MST mode as well) to avoid
+         * problems handling I/O errors later.
+         */
         pci_read_config_dword(pdev, addr1, &reg);
-        mode = hpt36x_find_mode(ap, adev->pio_mode);
-        mode &= ~0x8000000;     /* No FIFO in PIO */
-        mode &= ~0x30070000;    /* Leave config bits alone */
-        reg &= 0x30070000;      /* Strip timing bits */
-        pci_write_config_dword(pdev, addr1, reg | mode);
+        reg = ((reg & ~mask) | (clocks->timing & mask)) & ~0xc0000000;
+        pci_write_config_dword(pdev, addr1, reg);
+}
+
+/**
+ *      hpt366_set_piomode              -       PIO setup
+ *      @ap: ATA interface
+ *      @adev: device on the interface
+ *
+ *      Perform PIO mode setup.
+ */
+
+static void hpt366_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+        hpt366_set_mode(ap, adev, adev->pio_mode);
 }
 
 /**
@@ -271,28 +271,7 @@ static void hpt366_set_piomode(struct ata_port *ap, struct ata_device *adev)
 
 static void hpt366_set_dmamode(struct ata_port *ap, struct ata_device *adev)
 {
-        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-        u32 addr1, addr2;
-        u32 reg;
-        u32 mode;
-        u8 fast;
-
-        addr1 = 0x40 + 4 * (adev->devno + 2 * ap->port_no);
-        addr2 = 0x51 + 4 * ap->port_no;
-
-        /* Fast interrupt prediction disable, hold off interrupt disable */
-        pci_read_config_byte(pdev, addr2, &fast);
-        if (fast & 0x80) {
-                fast &= ~0x80;
-                pci_write_config_byte(pdev, addr2, fast);
-        }
-
-        pci_read_config_dword(pdev, addr1, &reg);
-        mode = hpt36x_find_mode(ap, adev->dma_mode);
-        mode |= 0x8000000;      /* FIFO in MWDMA or UDMA */
-        mode &= ~0xC0000000;    /* Leave config bits alone */
-        reg &= 0xC0000000;      /* Strip timing bits */
-        pci_write_config_dword(pdev, addr1, reg | mode);
+        hpt366_set_mode(ap, adev, adev->dma_mode);
 }
 
 static struct scsi_host_template hpt36x_sht = {