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, 7 insertions, 2 deletions

diff --git a/drivers/ide/pci/amd74xx.c b/drivers/ide/pci/amd74xx.c
index a7443f15b27a..84ed30cdb324 100644
--- a/drivers/ide/pci/amd74xx.c
+++ b/drivers/ide/pci/amd74xx.c
@@ -431,8 +431,13 @@ static void __devinit init_hwif_amd74xx(ide_hwif_t *hwif)
         if ((amd_config->flags & AMD_BAD_SWDMA) == 0)
                 hwif->swdma_mask = 0x07;
 
-        if (!hwif->udma_four)
-                hwif->udma_four = (amd_80w >> hwif->channel) & 1;
+        if (hwif->cbl != ATA_CBL_PATA40_SHORT) {
+                if ((amd_80w >> hwif->channel) & 1)
+                        hwif->cbl = ATA_CBL_PATA80;
+                else
+                        hwif->cbl = ATA_CBL_PATA40;
+        }
+
         hwif->ide_dma_check = &amd74xx_ide_dma_check;
         if (!noautodma)
                 hwif->autodma = 1;