sl82c105: DMA support code cleanup (take 4)

Fold the now equivalent code in the ide_dma_check() method into a mere call to
ide_use_dma().  Make config_for_dma() return non-zero if DMA mode has been set
and call it from the ide_dma_check() method instead of ide_dma_on().
Defer writing the DMA timings to the chip registers until DMA is really turned
on (and do not enable IORDY for DMA).
Remove unneeded code from the init_hwif() method, improve its overall looks.
Rename the dma_start(), ide_dma_check(), and ide_dma_lostirq() methods, and
also use more proper hwif->dma_command, fix printk() and comment in the latter
one as well.  While at it, cleanup style in several places.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 59 insertions, 89 deletions

diff --git a/drivers/ide/pci/sl82c105.c b/drivers/ide/pci/sl82c105.c
index ee6dd45a9ba7..fe3b4b91f854 100644
--- a/drivers/ide/pci/sl82c105.c
+++ b/drivers/ide/pci/sl82c105.c
@@ -100,59 +100,28 @@ static u8 sl82c105_tune_pio(ide_drive_t *drive, u8 pio)
 }
 
 /*
- * Configure the drive and the chipset for DMA
+ * Configure the drive for DMA.
+ * We'll program the chipset only when DMA is actually turned on.
  */
-static int config_for_dma (ide_drive_t *drive)
+static int config_for_dma(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        struct pci_dev *dev = hwif->pci_dev;
-        unsigned int reg;
-
         DBG(("config_for_dma(drive:%s)\n", drive->name));
 
-        reg = (hwif->channel ? 0x4c : 0x44) + (drive->select.b.unit ? 4 : 0);
-
         if (ide_config_drive_speed(drive, XFER_MW_DMA_2) != 0)
-                return 1;
+                return 0;
 
-        pci_write_config_word(dev, reg, 0x0240);
-
-        return 0;
+        return ide_dma_enable(drive);
 }
 
 /*
- * Check to see if the drive and
- * chipset is capable of DMA mode
+ * Check to see if the drive and chipset are capable of DMA mode.
  */
-
-static int sl82c105_check_drive (ide_drive_t *drive)
+static int sl82c105_ide_dma_check(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif        = HWIF(drive);
-
-        DBG(("sl82c105_check_drive(drive:%s)\n", drive->name));
-
-        do {
-                struct hd_driveid *id = drive->id;
+        DBG(("sl82c105_ide_dma_check(drive:%s)\n", drive->name));
 
-                if (!drive->autodma)
-                        break;
-
-                if (!id || !(id->capability & 1))
-                        break;
-
-                /* Consult the list of known "bad" drives */
-                if (__ide_dma_bad_drive(drive))
-                        break;
-
-                if (id->field_valid & 2) {
-                        if ((id->dma_mword & hwif->mwdma_mask) ||
-                            (id->dma_1word & hwif->swdma_mask))
-                                return 0;
-                }
-
-                if (__ide_dma_good_drive(drive) && id->eide_dma_time < 150)
-                        return 0;
-        } while (0);
+        if (ide_use_dma(drive) && config_for_dma(drive))
+                return 0;
 
         return -1;
 }
@@ -181,14 +150,14 @@ static inline void sl82c105_reset_host(struct pci_dev *dev)
  * This function is called when the IDE timer expires, the drive
  * indicates that it is READY, and we were waiting for DMA to complete.
  */
-static int sl82c105_ide_dma_lost_irq(ide_drive_t *drive)
+static int sl82c105_ide_dma_lostirq(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        struct pci_dev *dev = hwif->pci_dev;
-        u32 val, mask = hwif->channel ? CTRL_IDE_IRQB : CTRL_IDE_IRQA;
-        unsigned long dma_base = hwif->dma_base;
+        ide_hwif_t *hwif        = HWIF(drive);
+        struct pci_dev *dev     = hwif->pci_dev;
+        u32 val, mask           = hwif->channel ? CTRL_IDE_IRQB : CTRL_IDE_IRQA;
+        u8 dma_cmd;
 
-        printk("sl82c105: lost IRQ: resetting host\n");
+        printk("sl82c105: lost IRQ, resetting host\n");
 
         /*
          * Check the raw interrupt from the drive.
@@ -201,15 +170,15 @@ static int sl82c105_ide_dma_lost_irq(ide_drive_t *drive)
          * Was DMA enabled?  If so, disable it - we're resetting the
          * host.  The IDE layer will be handling the drive for us.
          */
-        val = inb(dma_base);
-        if (val & 1) {
-                outb(val & ~1, dma_base);
+        dma_cmd = inb(hwif->dma_command);
+        if (dma_cmd & 1) {
+                outb(dma_cmd & ~1, hwif->dma_command);
                 printk("sl82c105: DMA was enabled\n");
         }
 
         sl82c105_reset_host(dev);
 
-        /* ide_dmaproc would return 1, so we do as well */
+        /* __ide_dma_lostirq would return 1, so we do as well */
         return 1;
 }
 
@@ -221,10 +190,10 @@ static int sl82c105_ide_dma_lost_irq(ide_drive_t *drive)
  * The generic IDE core will have disabled the BMEN bit before this
  * function is called.
  */
-static void sl82c105_ide_dma_start(ide_drive_t *drive)
+static void sl82c105_dma_start(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        struct pci_dev *dev = hwif->pci_dev;
+        ide_hwif_t *hwif        = HWIF(drive);
+        struct pci_dev *dev     = hwif->pci_dev;
 
         sl82c105_reset_host(dev);
         ide_dma_start(drive);
@@ -232,8 +201,8 @@ static void sl82c105_ide_dma_start(ide_drive_t *drive)
 
 static int sl82c105_ide_dma_timeout(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        struct pci_dev *dev = hwif->pci_dev;
+        ide_hwif_t *hwif        = HWIF(drive);
+        struct pci_dev *dev     = hwif->pci_dev;
 
         DBG(("sl82c105_ide_dma_timeout(drive:%s)\n", drive->name));
 
@@ -241,14 +210,20 @@ static int sl82c105_ide_dma_timeout(ide_drive_t *drive)
         return __ide_dma_timeout(drive);
 }
 
-static int sl82c105_ide_dma_on (ide_drive_t *drive)
+static int sl82c105_ide_dma_on(ide_drive_t *drive)
 {
+        struct pci_dev *dev     = HWIF(drive)->pci_dev;
+        int rc, reg             = 0x44 + drive->dn * 4;
+
         DBG(("sl82c105_ide_dma_on(drive:%s)\n", drive->name));
 
-        if (config_for_dma(drive))
-                return 1;
-        printk(KERN_INFO "%s: DMA enabled\n", drive->name);
-        return __ide_dma_on(drive);
+        rc = __ide_dma_on(drive);
+        if (rc == 0) {
+                pci_write_config_word(dev, reg, 0x0200);
+
+                printk(KERN_INFO "%s: DMA enabled\n", drive->name);
+        }
+        return rc;
 }
 
 static void sl82c105_dma_off_quietly(ide_drive_t *drive)
@@ -272,8 +247,8 @@ static void sl82c105_dma_off_quietly(ide_drive_t *drive)
  */
 static void sl82c105_selectproc(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        struct pci_dev *dev = hwif->pci_dev;
+        ide_hwif_t *hwif        = HWIF(drive);
+        struct pci_dev *dev     = hwif->pci_dev;
         u32 val, old, mask;
 
         //DBG(("sl82c105_selectproc(drive:%s)\n", drive->name));
@@ -373,7 +348,7 @@ static unsigned int __devinit init_chipset_sl82c105(struct pci_dev *dev, const c
 }
 
 /*
- * Initialise the chip
+ * Initialise IDE channel
  */
 static void __devinit init_hwif_sl82c105(ide_hwif_t *hwif)
 {
@@ -398,11 +373,6 @@ static void __devinit init_hwif_sl82c105(ide_hwif_t *hwif)
          */
         hwif->drives[0].autotune = hwif->drives[1].autotune = 1;
 
-        hwif->atapi_dma = 0;
-        hwif->mwdma_mask = 0;
-        hwif->swdma_mask = 0;
-        hwif->autodma = 0;
-
         if (!hwif->dma_base)
                 return;
 
@@ -412,27 +382,27 @@ static void __devinit init_hwif_sl82c105(ide_hwif_t *hwif)
                  * Never ever EVER under any circumstances enable
                  * DMA when the bridge is this old.
                  */
-                printk("    %s: Winbond 553 bridge revision %d, BM-DMA disabled\n",
-                       hwif->name, rev);
-        } else {
-                hwif->atapi_dma = 1;
-                hwif->mwdma_mask = 0x04;
-
-                hwif->ide_dma_check = &sl82c105_check_drive;
-                hwif->ide_dma_on = &sl82c105_ide_dma_on;
-                hwif->dma_off_quietly = &sl82c105_dma_off_quietly;
-                hwif->ide_dma_lostirq = &sl82c105_ide_dma_lost_irq;
-                hwif->dma_start = &sl82c105_ide_dma_start;
-                hwif->ide_dma_timeout = &sl82c105_ide_dma_timeout;
-
-                if (!noautodma)
-                        hwif->autodma = 1;
-                hwif->drives[0].autodma = hwif->autodma;
-                hwif->drives[1].autodma = hwif->autodma;
-
-                if (hwif->mate)
-                        hwif->serialized = hwif->mate->serialized = 1;
+                printk("    %s: Winbond W83C553 bridge revision %d, "
+                       "BM-DMA disabled\n", hwif->name, rev);
+                return;
         }
+
+        hwif->atapi_dma  = 1;
+        hwif->mwdma_mask = 0x04;
+
+        hwif->ide_dma_check             = &sl82c105_ide_dma_check;
+        hwif->ide_dma_on                = &sl82c105_ide_dma_on;
+        hwif->dma_off_quietly           = &sl82c105_dma_off_quietly;
+        hwif->ide_dma_lostirq           = &sl82c105_ide_dma_lostirq;
+        hwif->dma_start                 = &sl82c105_dma_start;
+        hwif->ide_dma_timeout           = &sl82c105_ide_dma_timeout;
+
+        if (!noautodma)
+                hwif->autodma = 1;
+        hwif->drives[0].autodma = hwif->drives[1].autodma = hwif->autodma;
+
+        if (hwif->mate)
+                hwif->serialized = hwif->mate->serialized = 1;
 }
 
 static ide_pci_device_t sl82c105_chipset __devinitdata = {