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, 10 insertions, 8 deletions

diff --git a/drivers/ide/pci/siimage.c b/drivers/ide/pci/siimage.c
index 1a4444e7226a..1c3e35487893 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -933,16 +933,17 @@ static void __devinit init_iops_siimage(ide_hwif_t *hwif)
  *      interface.
  */
 
-static unsigned int __devinit ata66_siimage(ide_hwif_t *hwif)
+static u8 __devinit ata66_siimage(ide_hwif_t *hwif)
 {
         unsigned long addr = siimage_selreg(hwif, 0);
-        if (pci_get_drvdata(hwif->pci_dev) == NULL) {
-                u8 ata66 = 0;
+        u8 ata66 = 0;
+
+        if (pci_get_drvdata(hwif->pci_dev) == NULL)
                 pci_read_config_byte(hwif->pci_dev, addr, &ata66);
-                return (ata66 & 0x01) ? 1 : 0;
-        }
+        else
+                ata66 = hwif->INB(addr);
 
-        return (hwif->INB(addr) & 0x01) ? 1 : 0;
+        return (ata66 & 0x01) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 }
 
 /**
@@ -988,8 +989,9 @@ static void __devinit init_hwif_siimage(ide_hwif_t *hwif)
                 hwif->atapi_dma = 1;
 
         hwif->ide_dma_check = &siimage_config_drive_for_dma;
-        if (!(hwif->udma_four))
-                hwif->udma_four = ata66_siimage(hwif);
+
+        if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+                hwif->cbl = ata66_siimage(hwif);
 
         if (hwif->mmio) {
                 hwif->ide_dma_test_irq = &siimage_mmio_ide_dma_test_irq;