ide: add short cables support

This patch allows users to override both host and device side cable detection
with "ideX=ata66" kernel parameter.  Thanks to this it should be now possible
to use UDMA > 2 modes on systems (laptops mainly) which use short 40-pin cable
instead of 80-pin one.

Next patches add automatic detection of some systems using short cables.

Changes:

* Rename hwif->udma_four to hwif->cbl and make it u8.

* Convert all existing users accordingly (use ATA_CBL_* defines while at it).  

* Add ATA_CBL_PATA40_SHORT support to ide-iops.c:eighty_ninty_three().

* Use ATA_CBL_PATA40_SHORT for "ideX=ata66" kernel parameter.

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

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 8b219dd63024..1547c37f3332 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -394,14 +394,14 @@ static void piix_dma_clear_irq(ide_drive_t *drive)
         hwif->OUTB(dma_stat, hwif->dma_status);
 }
 
-static int __devinit piix_cable_detect(ide_hwif_t *hwif)
+static u8 __devinit piix_cable_detect(ide_hwif_t *hwif)
 {
         struct pci_dev *dev = hwif->pci_dev;
         u8 reg54h = 0, mask = hwif->channel ? 0xc0 : 0x30;
 
         pci_read_config_byte(dev, 0x54, &reg54h);
 
-        return (reg54h & mask) ? 1 : 0;
+        return (reg54h & mask) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 }
 
 /**
@@ -444,8 +444,8 @@ static void __devinit init_hwif_piix(ide_hwif_t *hwif)
         hwif->swdma_mask = 0x04;
 
         if (hwif->ultra_mask & 0x78) {
-                if (!hwif->udma_four)
-                        hwif->udma_four = piix_cable_detect(hwif);
+                if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+                        hwif->cbl = piix_cable_detect(hwif);
         }
 
         if (no_piix_dma)