[PATCH 2.4.21-pre4-ac4] nForce/AMD 80 wire IDE cable detection

[Zoltan Hidvegi]

amd74xx.c in 2.4.21-pre4-ac4 uses an uninitialized variable to set the
cable type.  I have made a simple fix that I have tried it with an MSI
K7N2G-ILSR nForce2 board.  With this patch the 80 wire cable on my
primary IDE is detected by the workaround, but the secondary IDE is
still incorrectly reported as 40 wire, so something may still be
wrong.  See below some IDE boot messages and the small patch.

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Zoli

NFORCE2: IDE controller at PCI slot 00:09.0
NFORCE2: chipset revision 162
NFORCE2: not 100% native mode: will probe irqs later
AMD_IDE: Bios didn't set cable bits corectly. Enabling workaround.
AMD_IDE: PCI device 10de:0065 (nVidia Corporation) (rev a2) UDMA100 controller o
n pci00:09.0
    ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:DMA
    ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:DMA, hdd:DMA
hda: WDC WD1200JB-75CRA0, ATA DISK drive
hdc: RIDATA DVD+RW DRIVE, ATAPI CD/DVD-ROM drive

----------AMD BusMastering IDE Configuration----------------
Driver Version:                     2.9
South Bridge:                       PCI device 10de:0065 (nVidia Corporation)
Revision:                           IDE 0xa2
Highest DMA rate:                   UDMA100
BM-DMA base:                        0xf000
PCI clock:                          33.3MHz
-----------------------Primary IDE-------Secondary IDE------
Prefetch Buffer:              yes                 yes
Post Write Buffer:            yes                 yes
Enabled:                      yes                 yes
Simplex only:                  no                  no
Cable Type:                   80w                 40w
-------------------drive0----drive1----drive2----drive3-----
Transfer Mode:       UDMA       DMA      UDMA       DMA
Address Setup:       30ns      90ns      30ns      90ns
Cmd Active:          90ns      90ns      90ns      90ns
Cmd Recovery:        30ns      30ns      30ns      30ns
Data Active:         90ns     330ns      90ns     330ns
Data Recovery:       30ns     270ns      30ns     270ns
Cycle Time:          20ns     600ns      60ns     600ns
Transfer Rate:   99.9MB/s   3.3MB/s  33.3MB/s   3.3MB/s

 --- drivers/ide/pci/amd74xx.c~	Fri Feb 14 10:22:25 2003
 +++ drivers/ide/pci/amd74xx.c	Tue Feb 25 11:31:53 2003
 @@ -309,7 +309,8 @@
  
  		case AMD_UDMA_100:
  			pci_read_config_byte(dev, AMD_CABLE_DETECT, &t);
 -			amd_80w = ((u & 0x3) ? 1 : 0) | ((u & 0xc) ? 2 : 0);
 +			amd_80w = ((t & 0x3) ? 1 : 0) | ((t & 0xc) ? 2 : 0);
 +			pci_read_config_dword(dev, AMD_UDMA_TIMING, &u);
  			for (i = 24; i >= 0; i -= 8)
  				if (((u >> i) & 4) && !(amd_80w & (1 << (1 - (i >> 4))))) {
  					printk(KERN_WARNING "AMD_IDE: Bios didn't set cable bits corectly. Enabling workaround.\n");