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_old.c b/drivers/ide/pci/pdc202xx_old.c
index ae628b86e18a..41ac4a94959f 100644
--- a/drivers/ide/pci/pdc202xx_old.c
+++ b/drivers/ide/pci/pdc202xx_old.c
@@ -152,8 +152,10 @@ static void pdc202xx_tune_drive(ide_drive_t *drive, u8 pio)
 static u8 pdc202xx_old_cable_detect (ide_hwif_t *hwif)
 {
         u16 CIS = 0, mask = (hwif->channel) ? (1<<11) : (1<<10);
+
         pci_read_config_word(hwif->pci_dev, 0x50, &CIS);
-        return (CIS & mask) ? 1 : 0;
+
+        return (CIS & mask) ? ATA_CBL_PATA40 : ATA_CBL_PATA80;
 }
 
 /*
@@ -357,8 +359,9 @@ static void __devinit init_hwif_pdc202xx(ide_hwif_t *hwif)
         hwif->dma_timeout = &pdc202xx_dma_timeout;
 
         if (hwif->pci_dev->device != PCI_DEVICE_ID_PROMISE_20246) {
-                if (!(hwif->udma_four))
-                        hwif->udma_four = (pdc202xx_old_cable_detect(hwif)) ? 0 : 1;
+                if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+                        hwif->cbl = pdc202xx_old_cable_detect(hwif);
+
                 hwif->dma_start = &pdc202xx_old_ide_dma_start;
                 hwif->ide_dma_end = &pdc202xx_old_ide_dma_end;
         }