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, 5 insertions, 4 deletions

diff --git a/drivers/ide/pci/sis5513.c b/drivers/ide/pci/sis5513.c
index ec0adad9ef61..4457c9d379f6 100644
--- a/drivers/ide/pci/sis5513.c
+++ b/drivers/ide/pci/sis5513.c
@@ -796,7 +796,7 @@ static unsigned int __devinit init_chipset_sis5513 (struct pci_dev *dev, const c
         return 0;
 }
 
-static unsigned int __devinit ata66_sis5513 (ide_hwif_t *hwif)
+static u8 __devinit ata66_sis5513(ide_hwif_t *hwif)
 {
         u8 ata66 = 0;
 
@@ -811,7 +811,8 @@ static unsigned int __devinit ata66_sis5513 (ide_hwif_t *hwif)
                 pci_read_config_byte(hwif->pci_dev, 0x48, &reg48h);
                 ata66 = (reg48h & mask) ? 0 : 1;
         }
-        return ata66;
+
+        return ata66 ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
 }
 
 static void __devinit init_hwif_sis5513 (ide_hwif_t *hwif)
@@ -841,8 +842,8 @@ static void __devinit init_hwif_sis5513 (ide_hwif_t *hwif)
         if (!chipset_family)
                 return;
 
-        if (!(hwif->udma_four))
-                hwif->udma_four = ata66_sis5513(hwif);
+        if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+                hwif->cbl = ata66_sis5513(hwif);
 
         if (chipset_family > ATA_16) {
                 hwif->ide_dma_check = &sis5513_config_xfer_rate;