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/it821x.c b/drivers/ide/pci/it821x.c
index 3aeb7f1b7916..8197b653ba1e 100644
--- a/drivers/ide/pci/it821x.c
+++ b/drivers/ide/pci/it821x.c
@@ -491,10 +491,10 @@ static int it821x_config_drive_for_dma (ide_drive_t *drive)
  *      the needed logic onboard.
  */
 
-static unsigned int __devinit ata66_it821x(ide_hwif_t *hwif)
+static u8 __devinit ata66_it821x(ide_hwif_t *hwif)
 {
         /* The reference driver also only does disk side */
-        return 1;
+        return ATA_CBL_PATA80;
 }
 
 /**
@@ -662,8 +662,9 @@ static void __devinit init_hwif_it821x(ide_hwif_t *hwif)
         hwif->mwdma_mask = 0x07;
 
         hwif->ide_dma_check = &it821x_config_drive_for_dma;
-        if (!(hwif->udma_four))
-                hwif->udma_four = ata66_it821x(hwif);
+
+        if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+                hwif->cbl = ata66_it821x(hwif);
 
         /*
          *      The BIOS often doesn't set up DMA on this controller