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, 6 insertions, 3 deletions

diff --git a/drivers/ide/pci/pdc202xx_new.c b/drivers/ide/pci/pdc202xx_new.c
index 0765dce6948e..ee5020df005d 100644
--- a/drivers/ide/pci/pdc202xx_new.c
+++ b/drivers/ide/pci/pdc202xx_new.c
@@ -225,7 +225,10 @@ static void pdcnew_tune_drive(ide_drive_t *drive, u8 pio)
 
 static u8 pdcnew_cable_detect(ide_hwif_t *hwif)
 {
-        return get_indexed_reg(hwif, 0x0b) & 0x04;
+        if (get_indexed_reg(hwif, 0x0b) & 0x04)
+                return ATA_CBL_PATA40;
+        else
+                return ATA_CBL_PATA80;
 }
 
 static int pdcnew_config_drive_xfer_rate(ide_drive_t *drive)
@@ -509,8 +512,8 @@ static void __devinit init_hwif_pdc202new(ide_hwif_t *hwif)
 
         hwif->ide_dma_check = &pdcnew_config_drive_xfer_rate;
 
-        if (!hwif->udma_four)
-                hwif->udma_four = pdcnew_cable_detect(hwif) ? 0 : 1;
+        if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+                hwif->cbl = pdcnew_cable_detect(hwif);
 
         if (!noautodma)
                 hwif->autodma = 1;