IDE cable detection on Apple PowerBook

[TOMARI Hisanobu]

Hello,

I'm using an OCZ PATA SSD on Apple PowerBook5,4 computer.
The IDE drive fails to recognize 80-conductor cable that
connects the drive to motherboard to fall back to UDMA33.

This patch fixes this behavior by assuming that the cable is
short-40pin when the model string matches "PowerBook5" and 
the motherboard detects 80c cable.

This patch is against drivers/ide/pmac.c in linux 2.6.28.8.

(before applying the patch) hdparm -i /dev/hda
/dev/hda:
 Timing buffered disk reads:   90 MB in  3.03 seconds =  29.73 MB/sec
(dmesg 2.6.26)
ide0: Found Apple UniNorth ATA-6 controller, bus ID 3, irq 39
Probing IDE interface ide0...
hda: CORE_PATA, ATA DISK drive
hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4
hda: drive side 80-wire cable detection failed, limiting max speed to UDMA33
hda: UDMA/33 mode selected

(after applying the patch) hdparm -i /dev/hda
/dev/hda:
 Timing buffered disk reads:  240 MB in  3.02 seconds =  79.42 MB/sec
(dmesg 2.6.28.8)
ide-pmac: Found Apple UniNorth ATA-6 controller (PCI), bus ID 3, irq 39
Probing IDE interface ide0...
hda: CORE_PATA, ATA DISK drive
hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4
hda: UDMA/100 mode selected
ide0 at 0xf102a000-0xf102a070,0xf102a160 on irq 39


-- 
TOMARI Hisanobu <posco.grubb at gmail.com>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ide-pmac-pbookcable.patch
Type: text/x-diff
Size: 1254 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20090318/70b923bb/attachment.patch>