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, 2 deletions

diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index f0be5f665a0e..92578b6832e9 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -574,7 +574,10 @@ u8 eighty_ninty_three (ide_drive_t *drive)
         ide_hwif_t *hwif = drive->hwif;
         struct hd_driveid *id = drive->id;
 
-        if (hwif->udma_four == 0)
+        if (hwif->cbl == ATA_CBL_PATA40_SHORT)
+                return 1;
+
+        if (hwif->cbl != ATA_CBL_PATA80)
                 goto no_80w;
 
         /* Check for SATA but only if we are ATA5 or higher */
@@ -600,7 +603,8 @@ no_80w:
 
         printk(KERN_WARNING "%s: %s side 80-wire cable detection failed, "
                             "limiting max speed to UDMA33\n",
-                            drive->name, hwif->udma_four ? "drive" : "host");
+                            drive->name,
+                            hwif->cbl == ATA_CBL_PATA80 ? "drive" : "host");
 
         drive->udma33_warned = 1;